Oppressive heat. Species extinctions. Pollution-choked skies.

This is the future that awaits the world unless humanity takes dramatic steps to end a series of mushrooming environmental crises, finds a new report from the United Nations Environment Programme (UNEP).

The seventh edition of the Global Environment Outlook (GEO-7) offers a stark vision of the decades to come. But its authors say the worst forecasts can still be avoided if countries quickly take meaningful steps to address climate change, nature, land and biodiversity loss, and pollution and waste.

“With a whole-of-government, whole-of-society effort humanity can still turn the ship around,” says Maarten Kappelle, Chief of Service in UNEP’s Office of Science. “But if countries continue to drag their collective feet, billions of people will face an uncertain future, especially those in the developing world.”

GEO-7, the work of 300 scientists, created a model of what the planet would look like in 2050 if nations continued to do three environmentally destructive things: pollute, pump out greenhouse gases, and destroy natural spaces. In the first of three stories about the report, here are some of the key findings of that modelling.

Crippling heat waves will become common

Planet-warming greenhouse gas emissions are expected to rise to 75 billion tonnes a year by 2050 – a 50 per cent jump from today. This will destabilize the climate and lead to a surge in heatwaves, which are expected to affect everyone on Earth – some 9.2 billion people – by 2050. Almost no corner of the planet will remain untouched by extreme heat.

Resource extraction will lead to widespread environmental devastation

Climate change alone is expected to shave 4 per cent off global gross domestic product annually by 2050. As temperatures rise and the crisis deepens, that number will rise to a staggering 20 per cent by 2100. That would be just a little less than the contraction the United States of America suffered during the Great Depression of the 1920s and 1930s. The downturn will be magnified by the effects of pollution and the disappearance of nature. The poor will suffer the most from this economic upheaval and the gap between them and the rich will continue to widen.

Air pollution will continue to plague cities – and take lives

GEO-7 foresees a slight drop in air pollution by 2050. But because of increasing urbanization, the absolute number of people exposed to airborne pollutants will rise. By 2050, 4.2 billion people will regularly inhale dangerous levels of one particularly problematic substance, PM 2.5. The report estimates that air-pollution-related deaths will cost the global economy US$18-25 trillion through 2060.

Natural spaces will continue to disappear at an alarming rate

The world will lose 1 million square kilometers of forests, peatlands, and other natural spaces. This is due to the expansion of cropland needed to feed a rising global population with a growing taste for meat. Because of the loss of ecosystems, the planet’s mean species abundance – a single number that captures the diversity and distribution of life – is expected to drop 3 per cent.

More people will suffer from the double whammy of droughts and floods

Climate change, left unchecked, will expose about 1.1 billion more people to heavy rains and an added 900 million people to intense drought by 2050. This climactic one-two punch will help push up to 132 million people into poverty and put another 24 million people at risk of hunger by 2040. By 2050, 3.3 billion people – one third of the planet – will face water stress.

The Earth may cross several environmental tipping points, with potentially disastrous results

GEO-7 says the world is approaching a series of climate-related thresholds from which there may be no return. The Greenland and Western Antarctic ice sheets could collapse, causing sea levels to rise 10 meters. Thawing permafrost could release massive amounts of methane, potent greenhouse gas, and supercharging warming. The Amazon rainforest may wither into a savannah, depriving the planet of one of its most important carbon sinks. Every warm-water coral would disappear, devastating undersea ecosystems and threatening fisheries around the world. Even ocean currents and Jet Stream could be affected, throwing the climate into disarray.

There is still time to save the planet – and us

As serious as the situation is, the Earth’s future is not written in stone, GEO-7 argues. There is time for humanity to address climate change, nature loss, and pollution. But it will take urgent and unprecedented changes in how countries govern their economies, handle materials and waste, generate energy, produce food, use raw materials, and treat the environment.

SOURCE: www.unep.org