Greenhouse gas emissions at 'all-time high', global warming at rapid rate

Greenhouse gas emissions have been found to be "at an all-time high", with human activity resulting in the equivalent of 54 gigatonnes of carbon dioxide being released into the atmosphere

Greenhouse gas (GHG) emissions have been found to be "at an all-time high", with human activity resulting in the equivalent of 54 gigatonnes of carbon dioxide being released into the atmosphere on average every year over the last decade.

A group of 50 leading scientists have said in an analysis that human-caused global warming has continued to increase at an "unprecedented rate" since the last major assessment of the climate system published two years ago.

One of the researchers said the analysis was a "timely wake-up call" and it comes as climate experts meet in Bonn, Germany, to prepare the ground for the major COP28 climate conference in the UAE in December, which will take stock of progress towards keeping global warming to 1.5 degrees Celsius by 2050.

The researchers wrote in the analysis that human-induced warming, largely caused by fossil fuel burning, reached an average of 1.14 degrees Celsius for the most recent decade (2013 to 2022) above pre-industrial levels, up from 1.07 degrees Celsius between 2010 and 2019.

It is now increasing at a pace of over 0.2 degrees Celsius per decade, they wrote in the journal Earth System Science Data.

In an initiative being led by the University of Leeds, UK, the scientists have developed an open data, open science platform - the Indicators of Global Climate Change. Its website will update information on key climate indicators every year.

Arguing that policymakers, climate negotiators and civil society groups need to have access to the latest and robust scientific evidence for decision-making, the scientists said that these key climate indicators have changed since the publication of the UN's Intergovernmental Panel on Climate Change's (IPCC's) Sixth Assessment Working Group 1 report in 2021, which produced the key data that fed into the subsequent IPCC Sixth Synthesis Report.

While there has been a positive move away from burning coal, it has, in fact, added to global warming by reducing particulate pollution in the air, which has a cooling effect, the analysis noted.

Coordinator of the initiative, Piers Forster, Director of the Priestley Centre for Climate Futures at Leeds, said, "Long-term warming rates are currently at a long-term high, caused by highest-ever levels of greenhouse gas emissions. But there is evidence that the rate of increase in greenhouse gas emissions has slowed.

"We need to be nimble footed in the face of climate change. We need to change policy and approaches in the light of the latest evidence about the state of the climate system. Time is no longer on our side. Access to up-to-date information is vitally important."

Decline in remaining carbon budget, an estimate of how much carbon that can be released into the atmosphere to give a 50 per cent chance of keeping global temperature rise within 1.5 degrees Celsius, another major finding of the analysis, has been attributed to a combination of continued emissions since 2020 and updated estimates of human-induced warming.

The IPCC calculated in 2020 this budget to be around 500 gigatonnes of carbon dioxide.

By the start of 2023, the figure was roughly halved to 250 gigatonnes.

"Even though we are not yet at 1.5 degrees Celsius warming, the carbon budget will likely be exhausted in only a few years as we have a triple whammy of heating from very high CO2 emissions, heating from increases in other GHG emissions and heating from reductions in pollution.

"If we don't want to see the 1.5 degrees Celsius goal disappearing in our rearview mirror, the world must work much harder and urgently at bringing emissions down," said Forster.

Maisa Rojas Corradi, Minister of the Environment in Chile, IPCC author and a scientist involved in this study, said, "An annual update of key indicators of global change is critical in helping the international community and countries to keep the urgency of addressing the climate crisis at the top of the agenda and for evidence-based decision-making."

He said that Chile had a climate change law aimed at aligning government-wide policies with climate action.