Tag Archives: global

Farm pests’ global advance threatens food security Updated for 2026





Coming soon to a farm near you: just about every possible type of pest that could take advantage of the ripening harvest in the nearby fields.

By 2050, according to new research in the journal Global Ecology and Biogeography, those opportunistic viruses, bacteria, fungi, blights, mildews, rusts, beetles, nematodes, flies, mites, spiders and caterpillars that farmers call pests will have saturated the world.

Wherever they can make a living, they will. None of this bodes well for food security in a world of nine billion people and increasingly rapid climate change.

Dan Bebber of the University of Exeter, UK, and colleagues decided to look at the state of pest populations worldwide.

They combed the literature to check the present status of 1,901 pests and pathogens and examined historical records of another 424 species. This research included the records made since 1822 by the agricultural development organization CABI.

Crop pests often emerge in one location, evolve and spread. That notorious potato pest the Colorado beetle, for instance, was first identified in the Rocky Mountains of the US in 1824.

On current trends, all pests will be everywhere by 2050

The scientists reasoned that climate change and international traffic made transmission of pests across oceans and other natural barriers increasingly probable, and tried to arrive at a rate of spread.

They found that more than one in 10 of all pest types can already be found in half of the countries that grow the host plants on which these pests depend. Most countries reported around one fifth of the pests that could theoretically make their home there.

Australia, China, France, India, Italy, the UK and the USA already had more than half of all the pests that could flourish in those countries. The pests that attack those tropical staples yams and cassava can be found in one third of the countries that grow those crops.

This trend towards saturation has increased steadily since the 1950s. So if the trend continues at the rate it has done during the late 20th century, then by 2050 farmers in western Europe and the US, and Japan, India and China will face saturation point.

They will be confronted with potential attack from just about all the pests that, depending on the local climate and conditions, their maize, rice, bananas, potatoes, soybeans and other crops could support.

If the world acts, it may not happen

“If crop pests continue to spread at current rates, many of the world’s biggest crop-producing nations will be inundated by the middle of the century, posing a grave threat to global food security”, Dr Bebber said.

Three kinds of tropical root knot nematode produce larvae that infect the roots of thousands of different plant species.

For example, the fungus Blumeria graminis causes powdery mildew on wheat and other grains; and a virus called Citrus tristeza, first identified by growers in Spain and Portugal in the 1930s, had by 2000 reached 105 out of the 145 countries that grow oranges, lemons, limes and grapefruit.

Predictions such as these are intended to be self-defeating: they present a warning of what might happen if no steps are taken.

“By unlocking the potential to understand the distribution of crop pests and diseases, we’re moving one step closer to protecting our ability to feed a growing global population”, said Timothy Holmes, of CABI’s Plantwise knowledge bank, one of the authors. “The hope is to turn data into positive action.”

 


 

Tim Radford writes for Climate News Network, where this article originates.

 

 




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A global plan for road expansion that doesn’t cost the earth Updated for 2026





“The best thing you could do for the Amazon is to blow up all the roads.” These might sound like the words of an eco-terrorist, but it’s actually a direct quote from Professor Eneas Salati, a forest climatologist and one of Brazil’s most respected scientists.

Many scientists share Salati’s anxieties because we’re living in the most explosive era of road expansion in human history.

The International Energy Agency (IEA) predicts that by 2050 we will have 60% more roads than we did in 2010. That’s about 25 million kilometres of new paved roads – enough to circle the Earth more than 600 times.

In new research published today in Nature, we’ve developed a global ‘roadmap’ of where to put those roads to avoid damaging the environment. Our maps are also available to the public on a new website.

Roads today are proliferating virtually everywhere – for exploiting timber, minerals, oil and natural gas; for promoting regional trade and development; and for building burgeoning networks of energy infrastructure such as hydroelectric dams, power lines and gas lines.

Security and development versus biodiversity

Even national security and paranoia play a role. The first major roads built in the Brazilian Amazon were motivated by fears that Colombia or the US might try to annex the Amazon and steal its valuable natural resources.

India’s current spate of road building along its northern frontier is all about defending its disputed territories from an increasingly strident China.

According to the IEA, around nine-tenths of new roads will be built in developing nations, which sustain the most biologically important ecosystems on Earth, such as tropical and subtropical rainforests and wildlife-rich savanna-woodlands.

Crucially, such environments also store billions of tonnes of carbon, harbour hundreds of indigenous cultures, and have a major stabilizing influence on the global climate.

‘Killer roads’ open up forests for logging, farms and hunting

Why are roads regarded as disasters for nature?

Far too often, when a new road cuts into a forest or wilderness, illegal poachers, miners, loggers or land speculators quickly invade – unleashing a Pandora’s box of environmental problems.

For instance, my colleagues and I recently found that 95% of all forest destruction in the Brazilian Amazon has occurred within 5 kilometres of roads. Other research has shown that major forest fires spike sharply within a few dozen kilometres of Amazon roads.

Notably, we also found that many Amazonian roads are illegal – for every kilometre of legal road, there were three kilometres of illegal roads.

The Congo Basin is reeling from a spree of forest-road building by industrial loggers, with over 50,000 kilometres of new roads bulldozed into the rainforest in recent years.

This has opened up the forest to a tsunami of hunting. The toll on wildlife has been appalling; in the last decade, for instance, around two-thirds of all forest elephants have been slaughtered for their valuable ivory tusks.

In Peru, a new highway slicing across the western Amazon has led to a massive influx of illegal gold miners into formerly pristine rainforests, turning them into virtual moonscapes and polluting entire river systems with the toxic mercury they use to separate the gold from river sediments.

The first cut is the cruellest

Many road researchers believe the only safe way to protect a wilderness is by ‘avoiding the first cut’ – keeping it road free. This is because an initial road opens up a forest to deforestation, which then spreads contagiously, like a series of tumors.

And that cancer quickly grows. An initial road slicing into a wilderness typically spawns a network of secondary and tertiary roads, allowing deforestation to easily metastasise.

For instance, the first major highway in the Amazon – completed in the early 1970s to link the cities of Belem and Brasilia – was initially just a razor-thin cut through the forest. Today, that narrow incision has grown into a 400-kilometre-wide slash of forest destruction across the entire eastern Amazon.

And yet, for all the environmental perils of roads, they are also an indispensable part of modern societies. Most economists love roads – seeing them as a cost-effective way to promote economic growth, encourage regional trade and provide access to natural resources and land suitable for agriculture.

How do we balance these two competing realities – between road lovers aspiring for wealth and social development, and road fearers hoping to avoid ecological Armageddon?

For those who want to know, a global roadmap

This vexing question has been the focus of a talented group of researchers I‘ve been leading over the past two years, from Harvard, Cambridge, Melbourne, Minnesota, Sheffield and James Cook Universities and the Conservation Strategy Fund.

Our scheme has two components. The first is a map that attempts to illustrate the natural values of all ecosystems worldwide. We built this map by combining data on biodiversity, endangered species, rare habitats, critical wilderness areas, and vital ecosystem services across the Earth.

We added in parks and other protected areas, as these are also high priorities for nature conservation.

The second component is a road-benefits map. It shows where roads could have the greatest benefits for humankind, especially for increasing food production.

Focusing on food is vital because, with continuing rapid population growth and changing human diets, global food demand is expected to double by 2050.

With roads, more food is grown, and reaches those that need it

Roads affect food because large expanses of the planet – especially in Sub-Saharan Africa and expanses of Asia and Latin America – are populated by small-scale farmers who produce much less food than they could if they had new or better roads.

Such roads could give them ready access to fertilizers, modern farming methods and urban markets to sell their crops.

In these regions most of the native vegetation has already been cleared, so intensifying farming shouldn’t have major environmental costs. In these contexts, new or better roads (along with other investments in modern farming methods) are a key way to help struggling farmers to boost their productivity.

A potential bonus of this strategy is that, as farming becomes more productive and rural livelihoods more prosperous, regions with better roads tend to act as ‘magnets’ – attracting people from elsewhere, such as the margins of vulnerable forests.

In this way, investing in better roads in appropriate areas can help to focus and intensify farming, accelerating food production while hopefully helping to spare other lands for nature conservation.

Conflict zones, but reasons to hope

By intersecting our environmental-values and road-benefits maps, we have estimated the relative risks and rewards of road building for Earth’s entire land surface – some 13.3 billion hectares in total.

In our map, green-toned areas are priorities for conservation where roads should be avoided if possible, and red-toned areas are priorities for agriculture.

Dark-toned areas are ‘conflict zones’ – where environmental and agricultural priorities are likely to clash. Light-coloured areas are lower priorities for both environment and farming.

The good news is that there are substantial areas of the planet where agriculture can be improved with modest environmental costs.

But there are also massive conflict zones – in Sub-Saharan Africa, expanses of Central and South America, and much of the Asia-Pacific region, among others. These hotbeds of conflict often occur where human population growth is rapid and there are many locally endemic species – those with small geographic ranges that are especially vulnerable to intensive development.

A global plan for road expansion – in the right places

Our global roadmap is, admittedly, an exceedingly ambitious effort. Yet our hope is that our strategy can be incorporated with finer-scale local information to help inform and improve planning decisions at national and regional scales.

Our effort is a first step toward a vital goal: a global plan for road expansion. We’re not so naïve as to believe everyone will immediately adopt it, but such efforts are unquestionably a crucial priority.

There is precious little time to lose if we don’t want to see the world’s last wild places overwhelmed by an onslaught of roads, destructive development and the roar of fast-moving vehicles.

 


 

Bill Laurance is Distinguished Research Professor and Australian Laureate at James Cook University. He receives funding from the Australian Research Council and other scientific and philanthropic organisations. In addition to his appointment as Distinguished Research Professor and Australian Laureate at James Cook University, he also holds the Prince Bernhard Chair in International Nature Conservation at Utrecht University, Netherlands. This chair is co-sponsored by Utrecht University and WWF-Netherlands.

This article was originally published on The Conversation. Read the original article.

The Conversation

 




383322

A global plan for road expansion that doesn’t cost the earth Updated for 2026





“The best thing you could do for the Amazon is to blow up all the roads.” These might sound like the words of an eco-terrorist, but it’s actually a direct quote from Professor Eneas Salati, a forest climatologist and one of Brazil’s most respected scientists.

Many scientists share Salati’s anxieties because we’re living in the most explosive era of road expansion in human history.

The International Energy Agency (IEA) predicts that by 2050 we will have 60% more roads than we did in 2010. That’s about 25 million kilometres of new paved roads – enough to circle the Earth more than 600 times.

In new research published today in Nature, we’ve developed a global ‘roadmap’ of where to put those roads to avoid damaging the environment. Our maps are also available to the public on a new website.

Roads today are proliferating virtually everywhere – for exploiting timber, minerals, oil and natural gas; for promoting regional trade and development; and for building burgeoning networks of energy infrastructure such as hydroelectric dams, power lines and gas lines.

Security and development versus biodiversity

Even national security and paranoia play a role. The first major roads built in the Brazilian Amazon were motivated by fears that Colombia or the US might try to annex the Amazon and steal its valuable natural resources.

India’s current spate of road building along its northern frontier is all about defending its disputed territories from an increasingly strident China.

According to the IEA, around nine-tenths of new roads will be built in developing nations, which sustain the most biologically important ecosystems on Earth, such as tropical and subtropical rainforests and wildlife-rich savanna-woodlands.

Crucially, such environments also store billions of tonnes of carbon, harbour hundreds of indigenous cultures, and have a major stabilizing influence on the global climate.

‘Killer roads’ open up forests for logging, farms and hunting

Why are roads regarded as disasters for nature?

Far too often, when a new road cuts into a forest or wilderness, illegal poachers, miners, loggers or land speculators quickly invade – unleashing a Pandora’s box of environmental problems.

For instance, my colleagues and I recently found that 95% of all forest destruction in the Brazilian Amazon has occurred within 5 kilometres of roads. Other research has shown that major forest fires spike sharply within a few dozen kilometres of Amazon roads.

Notably, we also found that many Amazonian roads are illegal – for every kilometre of legal road, there were three kilometres of illegal roads.

The Congo Basin is reeling from a spree of forest-road building by industrial loggers, with over 50,000 kilometres of new roads bulldozed into the rainforest in recent years.

This has opened up the forest to a tsunami of hunting. The toll on wildlife has been appalling; in the last decade, for instance, around two-thirds of all forest elephants have been slaughtered for their valuable ivory tusks.

In Peru, a new highway slicing across the western Amazon has led to a massive influx of illegal gold miners into formerly pristine rainforests, turning them into virtual moonscapes and polluting entire river systems with the toxic mercury they use to separate the gold from river sediments.

The first cut is the cruellest

Many road researchers believe the only safe way to protect a wilderness is by ‘avoiding the first cut’ – keeping it road free. This is because an initial road opens up a forest to deforestation, which then spreads contagiously, like a series of tumors.

And that cancer quickly grows. An initial road slicing into a wilderness typically spawns a network of secondary and tertiary roads, allowing deforestation to easily metastasise.

For instance, the first major highway in the Amazon – completed in the early 1970s to link the cities of Belem and Brasilia – was initially just a razor-thin cut through the forest. Today, that narrow incision has grown into a 400-kilometre-wide slash of forest destruction across the entire eastern Amazon.

And yet, for all the environmental perils of roads, they are also an indispensable part of modern societies. Most economists love roads – seeing them as a cost-effective way to promote economic growth, encourage regional trade and provide access to natural resources and land suitable for agriculture.

How do we balance these two competing realities – between road lovers aspiring for wealth and social development, and road fearers hoping to avoid ecological Armageddon?

For those who want to know, a global roadmap

This vexing question has been the focus of a talented group of researchers I‘ve been leading over the past two years, from Harvard, Cambridge, Melbourne, Minnesota, Sheffield and James Cook Universities and the Conservation Strategy Fund.

Our scheme has two components. The first is a map that attempts to illustrate the natural values of all ecosystems worldwide. We built this map by combining data on biodiversity, endangered species, rare habitats, critical wilderness areas, and vital ecosystem services across the Earth.

We added in parks and other protected areas, as these are also high priorities for nature conservation.

The second component is a road-benefits map. It shows where roads could have the greatest benefits for humankind, especially for increasing food production.

Focusing on food is vital because, with continuing rapid population growth and changing human diets, global food demand is expected to double by 2050.

With roads, more food is grown, and reaches those that need it

Roads affect food because large expanses of the planet – especially in Sub-Saharan Africa and expanses of Asia and Latin America – are populated by small-scale farmers who produce much less food than they could if they had new or better roads.

Such roads could give them ready access to fertilizers, modern farming methods and urban markets to sell their crops.

In these regions most of the native vegetation has already been cleared, so intensifying farming shouldn’t have major environmental costs. In these contexts, new or better roads (along with other investments in modern farming methods) are a key way to help struggling farmers to boost their productivity.

A potential bonus of this strategy is that, as farming becomes more productive and rural livelihoods more prosperous, regions with better roads tend to act as ‘magnets’ – attracting people from elsewhere, such as the margins of vulnerable forests.

In this way, investing in better roads in appropriate areas can help to focus and intensify farming, accelerating food production while hopefully helping to spare other lands for nature conservation.

Conflict zones, but reasons to hope

By intersecting our environmental-values and road-benefits maps, we have estimated the relative risks and rewards of road building for Earth’s entire land surface – some 13.3 billion hectares in total.

In our map, green-toned areas are priorities for conservation where roads should be avoided if possible, and red-toned areas are priorities for agriculture.

Dark-toned areas are ‘conflict zones’ – where environmental and agricultural priorities are likely to clash. Light-coloured areas are lower priorities for both environment and farming.

The good news is that there are substantial areas of the planet where agriculture can be improved with modest environmental costs.

But there are also massive conflict zones – in Sub-Saharan Africa, expanses of Central and South America, and much of the Asia-Pacific region, among others. These hotbeds of conflict often occur where human population growth is rapid and there are many locally endemic species – those with small geographic ranges that are especially vulnerable to intensive development.

A global plan for road expansion – in the right places

Our global roadmap is, admittedly, an exceedingly ambitious effort. Yet our hope is that our strategy can be incorporated with finer-scale local information to help inform and improve planning decisions at national and regional scales.

Our effort is a first step toward a vital goal: a global plan for road expansion. We’re not so naïve as to believe everyone will immediately adopt it, but such efforts are unquestionably a crucial priority.

There is precious little time to lose if we don’t want to see the world’s last wild places overwhelmed by an onslaught of roads, destructive development and the roar of fast-moving vehicles.

 


 

Bill Laurance is Distinguished Research Professor and Australian Laureate at James Cook University. He receives funding from the Australian Research Council and other scientific and philanthropic organisations. In addition to his appointment as Distinguished Research Professor and Australian Laureate at James Cook University, he also holds the Prince Bernhard Chair in International Nature Conservation at Utrecht University, Netherlands. This chair is co-sponsored by Utrecht University and WWF-Netherlands.

This article was originally published on The Conversation. Read the original article.

The Conversation

 




383322

A global plan for road expansion that doesn’t cost the earth Updated for 2026





“The best thing you could do for the Amazon is to blow up all the roads.” These might sound like the words of an eco-terrorist, but it’s actually a direct quote from Professor Eneas Salati, a forest climatologist and one of Brazil’s most respected scientists.

Many scientists share Salati’s anxieties because we’re living in the most explosive era of road expansion in human history.

The International Energy Agency (IEA) predicts that by 2050 we will have 60% more roads than we did in 2010. That’s about 25 million kilometres of new paved roads – enough to circle the Earth more than 600 times.

In new research published today in Nature, we’ve developed a global ‘roadmap’ of where to put those roads to avoid damaging the environment. Our maps are also available to the public on a new website.

Roads today are proliferating virtually everywhere – for exploiting timber, minerals, oil and natural gas; for promoting regional trade and development; and for building burgeoning networks of energy infrastructure such as hydroelectric dams, power lines and gas lines.

Security and development versus biodiversity

Even national security and paranoia play a role. The first major roads built in the Brazilian Amazon were motivated by fears that Colombia or the US might try to annex the Amazon and steal its valuable natural resources.

India’s current spate of road building along its northern frontier is all about defending its disputed territories from an increasingly strident China.

According to the IEA, around nine-tenths of new roads will be built in developing nations, which sustain the most biologically important ecosystems on Earth, such as tropical and subtropical rainforests and wildlife-rich savanna-woodlands.

Crucially, such environments also store billions of tonnes of carbon, harbour hundreds of indigenous cultures, and have a major stabilizing influence on the global climate.

‘Killer roads’ open up forests for logging, farms and hunting

Why are roads regarded as disasters for nature?

Far too often, when a new road cuts into a forest or wilderness, illegal poachers, miners, loggers or land speculators quickly invade – unleashing a Pandora’s box of environmental problems.

For instance, my colleagues and I recently found that 95% of all forest destruction in the Brazilian Amazon has occurred within 5 kilometres of roads. Other research has shown that major forest fires spike sharply within a few dozen kilometres of Amazon roads.

Notably, we also found that many Amazonian roads are illegal – for every kilometre of legal road, there were three kilometres of illegal roads.

The Congo Basin is reeling from a spree of forest-road building by industrial loggers, with over 50,000 kilometres of new roads bulldozed into the rainforest in recent years.

This has opened up the forest to a tsunami of hunting. The toll on wildlife has been appalling; in the last decade, for instance, around two-thirds of all forest elephants have been slaughtered for their valuable ivory tusks.

In Peru, a new highway slicing across the western Amazon has led to a massive influx of illegal gold miners into formerly pristine rainforests, turning them into virtual moonscapes and polluting entire river systems with the toxic mercury they use to separate the gold from river sediments.

The first cut is the cruellest

Many road researchers believe the only safe way to protect a wilderness is by ‘avoiding the first cut’ – keeping it road free. This is because an initial road opens up a forest to deforestation, which then spreads contagiously, like a series of tumors.

And that cancer quickly grows. An initial road slicing into a wilderness typically spawns a network of secondary and tertiary roads, allowing deforestation to easily metastasise.

For instance, the first major highway in the Amazon – completed in the early 1970s to link the cities of Belem and Brasilia – was initially just a razor-thin cut through the forest. Today, that narrow incision has grown into a 400-kilometre-wide slash of forest destruction across the entire eastern Amazon.

And yet, for all the environmental perils of roads, they are also an indispensable part of modern societies. Most economists love roads – seeing them as a cost-effective way to promote economic growth, encourage regional trade and provide access to natural resources and land suitable for agriculture.

How do we balance these two competing realities – between road lovers aspiring for wealth and social development, and road fearers hoping to avoid ecological Armageddon?

For those who want to know, a global roadmap

This vexing question has been the focus of a talented group of researchers I‘ve been leading over the past two years, from Harvard, Cambridge, Melbourne, Minnesota, Sheffield and James Cook Universities and the Conservation Strategy Fund.

Our scheme has two components. The first is a map that attempts to illustrate the natural values of all ecosystems worldwide. We built this map by combining data on biodiversity, endangered species, rare habitats, critical wilderness areas, and vital ecosystem services across the Earth.

We added in parks and other protected areas, as these are also high priorities for nature conservation.

The second component is a road-benefits map. It shows where roads could have the greatest benefits for humankind, especially for increasing food production.

Focusing on food is vital because, with continuing rapid population growth and changing human diets, global food demand is expected to double by 2050.

With roads, more food is grown, and reaches those that need it

Roads affect food because large expanses of the planet – especially in Sub-Saharan Africa and expanses of Asia and Latin America – are populated by small-scale farmers who produce much less food than they could if they had new or better roads.

Such roads could give them ready access to fertilizers, modern farming methods and urban markets to sell their crops.

In these regions most of the native vegetation has already been cleared, so intensifying farming shouldn’t have major environmental costs. In these contexts, new or better roads (along with other investments in modern farming methods) are a key way to help struggling farmers to boost their productivity.

A potential bonus of this strategy is that, as farming becomes more productive and rural livelihoods more prosperous, regions with better roads tend to act as ‘magnets’ – attracting people from elsewhere, such as the margins of vulnerable forests.

In this way, investing in better roads in appropriate areas can help to focus and intensify farming, accelerating food production while hopefully helping to spare other lands for nature conservation.

Conflict zones, but reasons to hope

By intersecting our environmental-values and road-benefits maps, we have estimated the relative risks and rewards of road building for Earth’s entire land surface – some 13.3 billion hectares in total.

In our map, green-toned areas are priorities for conservation where roads should be avoided if possible, and red-toned areas are priorities for agriculture.

Dark-toned areas are ‘conflict zones’ – where environmental and agricultural priorities are likely to clash. Light-coloured areas are lower priorities for both environment and farming.

The good news is that there are substantial areas of the planet where agriculture can be improved with modest environmental costs.

But there are also massive conflict zones – in Sub-Saharan Africa, expanses of Central and South America, and much of the Asia-Pacific region, among others. These hotbeds of conflict often occur where human population growth is rapid and there are many locally endemic species – those with small geographic ranges that are especially vulnerable to intensive development.

A global plan for road expansion – in the right places

Our global roadmap is, admittedly, an exceedingly ambitious effort. Yet our hope is that our strategy can be incorporated with finer-scale local information to help inform and improve planning decisions at national and regional scales.

Our effort is a first step toward a vital goal: a global plan for road expansion. We’re not so naïve as to believe everyone will immediately adopt it, but such efforts are unquestionably a crucial priority.

There is precious little time to lose if we don’t want to see the world’s last wild places overwhelmed by an onslaught of roads, destructive development and the roar of fast-moving vehicles.

 


 

Bill Laurance is Distinguished Research Professor and Australian Laureate at James Cook University. He receives funding from the Australian Research Council and other scientific and philanthropic organisations. In addition to his appointment as Distinguished Research Professor and Australian Laureate at James Cook University, he also holds the Prince Bernhard Chair in International Nature Conservation at Utrecht University, Netherlands. This chair is co-sponsored by Utrecht University and WWF-Netherlands.

This article was originally published on The Conversation. Read the original article.

The Conversation

 




383322

A global plan for road expansion that doesn’t cost the earth Updated for 2026





“The best thing you could do for the Amazon is to blow up all the roads.” These might sound like the words of an eco-terrorist, but it’s actually a direct quote from Professor Eneas Salati, a forest climatologist and one of Brazil’s most respected scientists.

Many scientists share Salati’s anxieties because we’re living in the most explosive era of road expansion in human history.

The International Energy Agency (IEA) predicts that by 2050 we will have 60% more roads than we did in 2010. That’s about 25 million kilometres of new paved roads – enough to circle the Earth more than 600 times.

In new research published today in Nature, we’ve developed a global ‘roadmap’ of where to put those roads to avoid damaging the environment. Our maps are also available to the public on a new website.

Roads today are proliferating virtually everywhere – for exploiting timber, minerals, oil and natural gas; for promoting regional trade and development; and for building burgeoning networks of energy infrastructure such as hydroelectric dams, power lines and gas lines.

Security and development versus biodiversity

Even national security and paranoia play a role. The first major roads built in the Brazilian Amazon were motivated by fears that Colombia or the US might try to annex the Amazon and steal its valuable natural resources.

India’s current spate of road building along its northern frontier is all about defending its disputed territories from an increasingly strident China.

According to the IEA, around nine-tenths of new roads will be built in developing nations, which sustain the most biologically important ecosystems on Earth, such as tropical and subtropical rainforests and wildlife-rich savanna-woodlands.

Crucially, such environments also store billions of tonnes of carbon, harbour hundreds of indigenous cultures, and have a major stabilizing influence on the global climate.

‘Killer roads’ open up forests for logging, farms and hunting

Why are roads regarded as disasters for nature?

Far too often, when a new road cuts into a forest or wilderness, illegal poachers, miners, loggers or land speculators quickly invade – unleashing a Pandora’s box of environmental problems.

For instance, my colleagues and I recently found that 95% of all forest destruction in the Brazilian Amazon has occurred within 5 kilometres of roads. Other research has shown that major forest fires spike sharply within a few dozen kilometres of Amazon roads.

Notably, we also found that many Amazonian roads are illegal – for every kilometre of legal road, there were three kilometres of illegal roads.

The Congo Basin is reeling from a spree of forest-road building by industrial loggers, with over 50,000 kilometres of new roads bulldozed into the rainforest in recent years.

This has opened up the forest to a tsunami of hunting. The toll on wildlife has been appalling; in the last decade, for instance, around two-thirds of all forest elephants have been slaughtered for their valuable ivory tusks.

In Peru, a new highway slicing across the western Amazon has led to a massive influx of illegal gold miners into formerly pristine rainforests, turning them into virtual moonscapes and polluting entire river systems with the toxic mercury they use to separate the gold from river sediments.

The first cut is the cruellest

Many road researchers believe the only safe way to protect a wilderness is by ‘avoiding the first cut’ – keeping it road free. This is because an initial road opens up a forest to deforestation, which then spreads contagiously, like a series of tumors.

And that cancer quickly grows. An initial road slicing into a wilderness typically spawns a network of secondary and tertiary roads, allowing deforestation to easily metastasise.

For instance, the first major highway in the Amazon – completed in the early 1970s to link the cities of Belem and Brasilia – was initially just a razor-thin cut through the forest. Today, that narrow incision has grown into a 400-kilometre-wide slash of forest destruction across the entire eastern Amazon.

And yet, for all the environmental perils of roads, they are also an indispensable part of modern societies. Most economists love roads – seeing them as a cost-effective way to promote economic growth, encourage regional trade and provide access to natural resources and land suitable for agriculture.

How do we balance these two competing realities – between road lovers aspiring for wealth and social development, and road fearers hoping to avoid ecological Armageddon?

For those who want to know, a global roadmap

This vexing question has been the focus of a talented group of researchers I‘ve been leading over the past two years, from Harvard, Cambridge, Melbourne, Minnesota, Sheffield and James Cook Universities and the Conservation Strategy Fund.

Our scheme has two components. The first is a map that attempts to illustrate the natural values of all ecosystems worldwide. We built this map by combining data on biodiversity, endangered species, rare habitats, critical wilderness areas, and vital ecosystem services across the Earth.

We added in parks and other protected areas, as these are also high priorities for nature conservation.

The second component is a road-benefits map. It shows where roads could have the greatest benefits for humankind, especially for increasing food production.

Focusing on food is vital because, with continuing rapid population growth and changing human diets, global food demand is expected to double by 2050.

With roads, more food is grown, and reaches those that need it

Roads affect food because large expanses of the planet – especially in Sub-Saharan Africa and expanses of Asia and Latin America – are populated by small-scale farmers who produce much less food than they could if they had new or better roads.

Such roads could give them ready access to fertilizers, modern farming methods and urban markets to sell their crops.

In these regions most of the native vegetation has already been cleared, so intensifying farming shouldn’t have major environmental costs. In these contexts, new or better roads (along with other investments in modern farming methods) are a key way to help struggling farmers to boost their productivity.

A potential bonus of this strategy is that, as farming becomes more productive and rural livelihoods more prosperous, regions with better roads tend to act as ‘magnets’ – attracting people from elsewhere, such as the margins of vulnerable forests.

In this way, investing in better roads in appropriate areas can help to focus and intensify farming, accelerating food production while hopefully helping to spare other lands for nature conservation.

Conflict zones, but reasons to hope

By intersecting our environmental-values and road-benefits maps, we have estimated the relative risks and rewards of road building for Earth’s entire land surface – some 13.3 billion hectares in total.

In our map, green-toned areas are priorities for conservation where roads should be avoided if possible, and red-toned areas are priorities for agriculture.

Dark-toned areas are ‘conflict zones’ – where environmental and agricultural priorities are likely to clash. Light-coloured areas are lower priorities for both environment and farming.

The good news is that there are substantial areas of the planet where agriculture can be improved with modest environmental costs.

But there are also massive conflict zones – in Sub-Saharan Africa, expanses of Central and South America, and much of the Asia-Pacific region, among others. These hotbeds of conflict often occur where human population growth is rapid and there are many locally endemic species – those with small geographic ranges that are especially vulnerable to intensive development.

A global plan for road expansion – in the right places

Our global roadmap is, admittedly, an exceedingly ambitious effort. Yet our hope is that our strategy can be incorporated with finer-scale local information to help inform and improve planning decisions at national and regional scales.

Our effort is a first step toward a vital goal: a global plan for road expansion. We’re not so naïve as to believe everyone will immediately adopt it, but such efforts are unquestionably a crucial priority.

There is precious little time to lose if we don’t want to see the world’s last wild places overwhelmed by an onslaught of roads, destructive development and the roar of fast-moving vehicles.

 


 

Bill Laurance is Distinguished Research Professor and Australian Laureate at James Cook University. He receives funding from the Australian Research Council and other scientific and philanthropic organisations. In addition to his appointment as Distinguished Research Professor and Australian Laureate at James Cook University, he also holds the Prince Bernhard Chair in International Nature Conservation at Utrecht University, Netherlands. This chair is co-sponsored by Utrecht University and WWF-Netherlands.

This article was originally published on The Conversation. Read the original article.

The Conversation

 




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Dams versus rivers – the global battle Updated for 2026





International Rivers has launched ‘The State of the World’s Rivers‘, an interactive online database that illustrates the role that dams have played in impoverishing the health of the world’s river basins.

The database shows how river fragmentation due to decades of dam-building is highly correlated with poor water quality and low biodiversity. Many of the world’s great river basins have been dammed to the point of serious decline, including the Mississippi, Yangtze, Paraná and Danube.

“The evidence we’ve compiled of planetary-scale impacts from river change is strong enough to warrant a major international focus on understanding the thresholds for ‘river change’ in the world’s major basins, and for the planet as a whole system”, said Jason Rainey, Executive Director of International Rivers.

For example, in the Middle East, decades of dam building in the Tigris-Euphrates basin have made it one of the most fragmented basins in the world.

As a result, the basin’s flooded grassland marshes have significantly decreased, leading to the disappearance of salt-tolerant vegetation that helped protect coastal areas, and a reduction in the plankton-rich waters that fertilize surrounding soils.

Habitat has decreased for 52 native fish species, migratory bird species, and mammals such as the water buffalo, antelopes and gazelles, and the jerboa.

Largely intact river basins now at risk

Meanwhile, some of the lesser-dammed basins, which are still relatively healthy at this point, are being targeted for major damming.

For example, the most biodiverse basin in the world, the Amazon, still provides habitat for roughly 14,000 species of mammals, 2,200 fish species, 1,500 bird species, and more than 1,000 amphibian species, like the Amazon River Dolphin, the Amazonian Manatee, and the Giant Otter. 

When all dam sizes are counted, Brazil plans to build an astonishing 412 dams in the Paraná and 254 in the Amazon basins. In Asia, China plans to continue to dam the Yangtze basin with at least another 94 planned large dams. At least 153 more dams are planned for the Mekong basin. 

Other basins that are high in biodiversity and water quality which are also targets for dam-building include the Tocantins, the Irrawaddy, the Congo, and the Zambezi.

Zachary Hurwitz, the coordinator of the project, said: “Basins that have been highly fragmented by dams provide important lessons for managing the relatively un-dammed basins that remain. Governments should turn their attention to river preservation to protect these basins’ valuable ecosystem services.”

Make damming ‘an option of last resort’

In addition to calling for an inter-governmental panel of experts to assess the State of the World’s Rivers, International Rivers recommends that no more dams be built on the mainstems of rivers, and that damming rivers becomes an option of last resort.

Created using Google Earth, the State of the World’s Rivers website maps nearly 6,000 dams in the world’s 50 major river basins, and ranks their ecological health according to indicators of river fragmentation, water quality and biodiversity.

The dams mapped are a small percentage of the more than 50,000 large dams that clog the arteries of our planet.

Users of the site can compare how each individual basin ranks in fragmentation, biodiversity, and water quality, and explore ten of the most significant river basins in more depth.

Each focus basin describes the threats from dam building, and allows users to see how dams can impact Ramsar Sites of Wetlands of International Importance and UNESCO World Heritage Sites.

 


 

Visit the State of the World’s Rivers database.

Watch video to learn how to navigate the site.

New York Times opinion piece ‘Large Dams Just Aren’t Worth the Cost’.

 

 




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Heat accumulating in the deep oceans has put global warming on pause Updated for 2026





There seem to have been a dozen or so explanations for why the Earth’s surface has warmed at a slower rate over the past 15 years compared to earlier decades.

This is perhaps not so surprising given the complexity of the climate system – the world’s best detectives will inevitably struggle to disentangle the factors which influence every lump and bump in the surface temperature record.

However, recent research implicates natural changes in the Pacific and Atlantic oceans as the prime culprits. Just as the apparently random motions in a river’s flow can shift before our eyes from one minute to the next, the gradual sloshing about of our vast ocean waters can influence Earth’s climate from one year to the next and from one decade to the next.

Natural variability and long term trends

It is clear that natural variability has and always will influence the climate. In addition to chaotic ocean fluctuations, changes in the brightness of the sun and variations in the frequency and intensity of volcanic eruptions (which cool the planet temporarily with sunlight-reflecting aerosol particles) influence the surface temperature.

The recent Intergovernmental Panel on Climate Change working report found that these natural factors have contributed toward the slowing rate of surface warming since 1998.

However, recent measurements of ocean temperature made by thousands of automated buoys and observations of Earth’s radiative energy budget by satellite instruments indicate that heating has continued at a rate equivalent to every person worldwide using about 20 kettles each to continuously boil the oceans.

This is consistent with what is expected from the rising atmospheric concentrations of greenhouse gases due to human activity. If anything, Earth’s heating rate increased between the 1985-1999 and 2000-2012 periods, despite a slowing in the rate of surface warming.

In search of the hidden heat – the Pacific?

So, how is it possible for increased heating to not directly correspond with surface warming?

The Earth’s heating is caused by an imbalance between the amount of absorbed sunlight and the heat emitted back to space. This surplus of heat is primarily absorbed by the oceans since they command the lion’s share of storage capacity compared with other parts of the climate system such as the land, the atmosphere or the cryosphere (ice and snow).

This large heat capacity of water is noticeable from the amount of time it takes to heat up your pan of vegetables. And there is a lot of water in the oceans – nearly a fifth of a cubic kilometre of water for each person on the planet.

Crucially, the temperature at the Earth’s surface depends upon where this heat is deposited in the oceans. If the upper levels warm, so too will the atmosphere above. However, if ocean circulations cause more heat to be drawn down to deeper depths (or less heat to be moved upward toward the sea surface) then surface temperatures will reflect this.

Recent research has implicated our largest ocean, the Pacific, as the most likely mechanism for subducting heat to deeper levels. Indeed, atmospheric and ocean conditions in the Pacific have been unusual in the past decade and computer simulations show that decades of slow surface warming despite rising greenhouse gas concentrations are associated with increased heating below 300m depth.

The mechanisms for heat absorption are less clear; the simulations show that similar patterns appearing to originate from the Pacific are associated with the draw-down of heat in the North Atlantic and Southern Ocean as well as the Pacific.

Or is it the Atlantic?

New research published in Science now shifts the focus towards the Atlantic Ocean. Xianyao Chen and Ka-Kit Tung of the University of Washington show that heating from rising greenhouse gas concentrations has preferentially warmed the ocean’s 300-1,500m layer since about 2000, thereby depriving the upper layers of this surplus heat and causing surface warming to slow.

The authors say these changes are part of a natural cycle of knock-on effects, involving ocean circulation responses to changes in how salty (and therefore dense) the upper Atlantic Ocean layers are.

This cycle is thought to last around 30 years, contributing a sustained cooling effect then a warming influence on surface temperatures. When combined with steady heating from greenhouse gas increases this leads to a ‘staircase’ effect of stable temperatures followed by rapid warming.

They argue the previous focus on the Pacific was based upon simulations that were unable to fully capture the intricacies of the Atlantic Ocean circulation. An observed decline in the North Atlantic Ocean circulation over recent years has also been identified as part of a longer-term shift based upon evidence from computer simulations.

Climate complexity disallows simple answers

The changes in ocean circulation have also been shown to influence seasonal extremes and, based upon the proposed Atlantic mechanism, may persist for another decade before rapid warming is re-established. However, the nature of internal ocean fluctuations means it is difficult to pin down timings with any confidence.

While it is human nature to seek a single cause for notable events, in reality the complexity of the climate system means that it is unlikely there is one simple reason for any extreme weather event or a decade of unusual climatic conditions.

Nevertheless, the recent hiatus in global surface warming has encouraged scientists to further scrutinise and learn in even finer detail than before the workings of our climate system.

 


 

Richard Allan is Professor of Climate Science at the University of Reading. He receives funding from the Natural Environment Research Council.

This article was originally published on The Conversation. Read the original article.

The Conversation

 




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