World to blow past key climate red-line, study finds

The world’s governments have failed to cut emissions enough to avoid severe climate disruption, a new study finds.

Commitments by national governments have made it ‘inevitable’ that average global temperatures will cross the critical threshold of 1.5 degrees Celsius (2.7 Fahrenheit) above pre-industrial levels, according to a landmark Department of Energy (DOE) document. ) published Thursday in Natural Climate Change.

These findings now focus on limiting emissions in a bid to keep warming as close to 1.5 degrees as possible – while trying to find ways to roll back warming, the DOE and its research partners from the University of Maryland and the Environmental Protection Agency (EPA) said.

“Let’s face it. We’re going to cross the 1.5-degree limit in the next two decades,” co-author scientist Haewon McJeon of the DOE’s Pacific Northwest National Laboratory said in a statement.

“That means we will go up to 1.6 or 1.7 degrees or more, and we have to get it down to 1.5. But how quickly we can bring it down is key,” McJeon added.

The study comes on the eve of President Biden’s visit on Friday to the United Nations Climate Change Conference (COP27) in Egypt, where he plans to tout US progress on clean energy and climate goals, according to the White House. Yet the study found that government actions in the United States and other countries have not kept pace with climate change.

In climate circles, the concept of exceeding a key threshold is called “overshoot”. But while overshooting the global warming threshold is now likely inevitable, different degrees of overshoot – and the speed of reduction in temperatures – lead to dramatically different results, the researchers found.

If countries simply met their existing climate pledges – which would see emissions of planet-warming gases decline indefinitely by around 2% per year – levels of carbon dioxide in the atmosphere will continue to rise throughout the end of the world. century, the researchers found.

This scenario leads to “irreversible and adverse consequences for human and natural systems,” lead author Gokul Iyer of the Joint Global Change Research Institute said in a statement.

Even this grim scenario is more optimistic than existing trends suggest. And despite Democrats passing a sweeping climate bill in late September, the Biden administration has been approving new oil and gas wells “at a much faster rate” than the Trump administration would. has done over an equivalent period, Politico reported earlier this month.

“We produce 12 million barrels of oil per day and by the end of this year we will produce 1 million barrels more per day than the day I took office. In fact, we are on track for record oil production in 2023,” Biden boasted in late October.

The burning of fossil fuels is almost universally recognized by scientists as the primary driver of climate change.

Over the past two decades, the fossil fuel industry has moved from outright denial of this link to a posture analogous to that of tobacco companies, which blame the damage caused by climate change on society as a whole, according to a 2021 study in One Earth.

In the most ambitious scenarios explored by DOE researchers, delay gives way to quick action. In these models, countries are expected to rapidly reduce their greenhouse gas emissions – largely released by the burning of fossil fuels – until 2030.

This pathway would bring global net zero carbon dioxide by 2057 – and with it a drastic slowdown in the processes that drive global warming, the researchers found.

This path would involve rapid scaling up of emissions reduction technologies – from electric vehicles to hydrogen and wind power and massive reductions in the use of carbon-based energy, according to the study. It would also require a huge scale-up of technologies such as carbon capture, to extract planet-warming carbon dioxide from the atmosphere, the researchers found.

In the 2015 Paris Climate Agreement, the world’s governments pledged to stay below 2 degrees Celsius of warming and to stay “as close to 1.5 degrees as possible”.

This 2 degree figure marks a red line from which the worst climate impacts could be avoided, but from which serious disruptions begin to appear – sowing discord, drought and disease far more dramatic than if global warming were to occur. maintained at 1.5 degrees.

Extreme heat waves would also affect more than twice as many of the world’s population in the 2-degree world as in the 1.5-degree world, according to a US government study.

At 2 degrees, biodiversity loss also doubles or triples from expected levels at 1.5 degrees, as does the number of ecosystems shifting from one form to another – such as forest to savannah or scrubland , according to the 2018 UN study

The higher warming threshold also results in significantly more severe declines in major cereal yields and declines in annual peach yields.

One fact that helps explain this dramatic drop in available fish protein: at 1.5 degrees coral reefs suffer severe declines, but at 2 degrees they all but disappear.

According to a UN report from late October, the world is far from the emission reductions needed to keep warming even to 2 degrees Celsius.

To keep warming below 2 degrees, governments around the world – especially big emitters like the US, China, India and Russia – would need to cut their emissions by 30%.

The DOE researchers pointed out that world leaders are moving much faster to step up their plans to cut emissions.

“Acting quickly means reaching net zero promises sooner, decarbonizing faster and meeting more ambitious emissions targets,” Iyer said.

“Every little bit counts, and you need a combination of it all. But our results show that the most important thing is to do it early. I do now, really.

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