Saturday, November 27

The decisive climate summit: this is what is at stake at Cop26 | Cop26

Cop26 may involve dozens of world leaders, cost billions of pounds, generate heaps of technical jargon, and be billed as the last chance to prevent dire global warming, but in its simplest form, the climate conference in Glasgow is a debate. on marking or risk reduction. .



The world has already warmed about 1.1 ° C since the Industrial Revolution. Even at this level, delegates no longer need to read scientific studies to understand how 200 years of emissions, exhaust gases and burning trees have destabilized the climate. All they have to do is look out the window or read recent global and local headlines. The host city, Glasgow, has just had its hottest summer on record. Globally, the summer of 2021 saw record temperatures, fires and floods around the world, killing hundreds in northwestern America, suffocating swaths of Siberia, flooding German cities and drowning subway commuters in China.

The heat has continued into the fall. At least four nations have experienced their warmest October days on record: Iran (46 ° C), Morocco (43.5 ° C), China (38.9 ° C) and South Korea (32.3 ° C). This is not an exception. As with the human body, the difference between a healthy temperature and a planetary fever can be less than 1 ° C. The last 10 years were the hottest decade on Earth since measurements began. Even at the current level, the UN Secretary General, António Guterres, has declared a “red code for humanity.” But it is too late to stop at this level because additional heating has already been built into the system.

1.5 ° C to 2 ° C

The main goal of Cop26 is to push the world as low as possible within this target band, which was established under the Paris agreement. 1.5C is considered the safest climate landing zone humanity could still reach. A slip of even half a degree would substantially increase the risks, according to the world’s leading climate scientists at the UN Intergovernmental Panel on Climate Change. Their computer models suggest that 420 million more people would be frequently exposed to extreme heat waves and heat-related deaths would rise twice as fast if temperatures reached 2 ° C instead of 1.5 ° C.

That half a degree would mean significantly more climate-related water stress, hunger and poverty, particularly in the poorest parts of the world. In the Sahel, the Amazon, southern Africa, central Europe and the Mediterranean, the risk to food security would be rated “high” rather than “medium”. In South Africa and the Mediterranean, the probability of extreme drought would be substantial, while economic growth would be more affected, especially in Africa, India, Southeast Asia, Brazil and Mexico.

Villagers gather around a tanker for the supply of drinking water in Latur, India
People gather around a tanker to stock up on drinking water in Latur, India. Photograph: Satish Bate / Getty Images

The other inhabitants of Earth would suffer much more with half a degree less room to breathe. At 2 ° C, 18% of insect species, 16% of plants and 8% of vertebrates are projected to lose half of their habitats, at least twice the proportions at 1.5 ° C This would put more stress on food production, pollination, water quality and other biological components of the planetary life support system.

The Amazon and other rainforests are also less likely to survive. The hotter, drier, and more fragmented these ecosystems become, the greater the risk that they will degrade in dry savannas. At 2 ° C, warm spells are projected to be one month longer than at 1.5 ° C, dry spells twice as long, and extreme temperatures three times more likely.

For the world’s oceans, 2 ° C instead of 1.5 ° C would mean increased ocean acidification, oxygen depletion, and more dead zones. This would increase the pressure on the fisheries and give the corals a minimal chance of survival.

Raising the temperature by that half a degree would make ice-free Arctic summers 10 times more likely and expose up to 2.5 million square kilometers of permafrost to melt. By the end of this century, sea levels are likely to rise at least 10 cm more than it would at 1.5 ° C, leaving 10.4 million people more vulnerable to flooding. That half a degree would increase the possibility of greater systemic risks, perhaps through a single massive event, such as the rupture of a large Antarctic glacier, or in the form of a cascade of multiple tipping points. But rather than a cliff that humanity collapses from, 2C is more likely just another notch on the dial. Following current trends, it will not be the last.

2C to 3C

The world is on the way to becoming 2.7 ° C warmer, the UN calculated last month. Patricia Espinosa, the UN’s top climate negotiator, said this was “a great cause for concern.” If countries lose faith in the Paris process and withdraw or back down, as the United States briefly did under Donald Trump and Brazil now under Jair Bolsonaro, temperatures could easily escalate beyond 3 ° C.

With this level of heating, the projected duration of the average drought increases to 10 months, compared to 2 months at 1.5 ° C, while the area burned by wildfires doubles. In Britain, the number of hot days would likely double and maximum temperatures would approach 40 ° C. Add another half a degree of global warming and ice-free summers in the Arctic are almost certain every year, while the risk of Marine heat waves, which can devastate fish and crustacean populations, are likely to be 41 times greater than in the pre-industrial era.

A person walks along a road in a drought-prone region of Madagascar
A person walks along a road in a drought-prone region of Madagascar. Photograph: Rijasolo / AFP / Getty Images

At 4 ° C, the global excess deaths due to heat are likely to increase six times faster than it would at 1.5 ° C. Add another half degree and the picture will look even more apocalyptic with two-thirds of the time. plants, insects and invertebrates that will likely lose more than half their climatic range, compared to about 6% at 1.5 ° C. Forests, wetlands and other regions of the planet rich in nature would be unrecognizable, as well than many coastal regions, and sea levels are likely to rise more than a meter by the end of the century.

Marking down

Those risks can be reduced if governments step up carbon reduction ambitions in Glasgow. “This is one of the most important police officers we’ve had in a long time,” said Jennifer Morgan, CEO of Greenpeace. “At a fundamental level, what is at stake is whether the world’s leaders are going to treat the climate as the emergency that it is and make a series of decisions to keep 1.5 ° C in sight.”

There have been advances. Over the past two years, net zero announcements by the UK, the EU, the US, Japan, South Korea and China have raised hopes. More than 100 countries have improved their plans and others continue to arrive. This month, Turkey finally ratified the Paris agreement and promised to reach a CO2 peak by 2035. Shortly before, South Africa pledged to cut its 2030 emissions cap by a third.

Carbon tracker calculate all commitments And announcements through November 2020 could limit global warming to 2.1 ° C if all countries deliver on their promises. Given that six of the 10 largest emitting countries have yet to reveal new plans, there is a chance that this will get even closer to 1.5 ° C in the coming weeks.

The richest countries in the world must take the initiative. According to the World Resources Institute, the action of the G20 alone could limit warming to 1.7 ° C.

For Bob Ward of the Grantham Research Institute on Climate Change, the wish list includes emissions from China that peaked five years in early 2025 and India setting a net zero target by mid-century, with the United States the EU and UK setting strong short-term carbon targets. reductions and make up for the $ 20 billion a year shortfall in climate finance support for poor nations. “The worst outcome would be for rich countries to be perceived as unreliable partners for developing countries, undermining all other parts of the negotiations and raising serious doubts as to whether the Paris agreement will ever be implemented,” he said.

Protesters hold banners during a climate protest in Johannesburg in 2019
Protesters hold signs during a climate protest in Johannesburg in 2019. Photograph: Denis Farrell / AP

Along with international solidarity, Glasgow will be a test of credibility. “What we are looking for in Glasgow are not more declarations and commitments, but credible plans that we can analyze,” said Chris Rapley, professor of climate science at University College London.

Rapley said the UK and many other governments have gotten away with vague promises from Paris. Others, like Brazil and Australia, have backtracked or tried to manipulate their carbon accounts. “Six years have passed. We have been burning the carbon budget despite the Covid lockdown. Now there is even less time. Cop26 should be where we go, from promises to strict plans that will get us as close to 1.5 ° C as possible. “

Erosion caused by melting permafrost tundra and disappearance of sea ice in Alaska's Yukon Delta
Erosion caused by melting permafrost tundra and disappearance of sea ice in Alaska’s Yukon Delta. Photograph: Mark Ralston / AFP / Getty Images

The best result would be a great bargain, a Glasgow pact, which puts out 1.5 degrees Celsius. The worst would be a unit breakdown that increases the possibility of scorching temperatures above 3 ° C. Most likely, there is something in between.

Lauri Myllyvirta of the Clean Air and Energy Research Center says a “realistic successful outcome” would be concrete and traceable steps between now and 2025 to achieve net zero targets, new commitments from countries like India, Russia, Saudi Arabia and Indonesia that they have yet to update their nationally determined contributions, and a clear message from China, the US, the EU and Japan that the financial tap for coal projects has been closed forever, while the cash channel for renewable energies will be opened more.

Public pressure will be crucial. Greenpeace’s Morgan said he was more hopeful than at the beginning of the year. “People are participating in all of this. The movements are coming together and getting stronger and you start to see a response from politicians about it. There is a lot of positive energy … I think what we will get is a very strong demonstration of public support around the world for a more systemic transformation and leaders will be intimidated and brave for that. But I don’t know if they will bow down and have the courage that is required at this time. It is an incredible moment ”.

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