Scientists Warn: World Warming at a Record 0.2 C per Decade

Record-high greenhouse gas emissions and shrinking air pollution have caused an unprecedented acceleration in global warming, 50 leading scientists warned Thursday in a comprehensive update on climate science.

From 2013 to 2022, “human-caused warming will increase at an unprecedented rate of more than 0.2°C per decade,” they report in a peer-reviewed study targeting policymakers.

Average annual emissions over the same period reached an all-time high of 54 billion tons of carbon dioxide₂ Or the equivalent of other gases – about 1,700 tons every second.

World leaders will confront the new data at the critical COP28 climate summit later this year in Dubai, where the “Global Assessment” at United Nations talks will assess progress toward the goals of the 2015 Paris Agreement on temperature.

The findings appear to close the door on limiting global warming under the Paris Treaty’s more ambitious 1.5C target, long identified as a sentinel for a relatively climate-safe world, though it still suffers severe impacts.

“Although we’re not yet at a 1.5°C rise, the carbon budget” – the amount of greenhouse gases humanity could emit without going over that limit – “is likely to be depleted,” said lead author Pierce Forster, a research physicist. In just a few years.” Professor at the University of Leeds.

That budget has shrunk by half since the UN’s climate science advisory body, the Intergovernmental Panel on Climate Change (IPCC), collected data for its last benchmark report in 2021, according to Forrester and her colleagues, many of whom are core contributors to the IPCC. concerned with climate change.

Unintended consequences

For a coin toss to have a chance of staying below the 1.5°C threshold, emissions of carbon dioxide, methane and other warming engines from burning fossil fuels must not exceed 250 billion tons, they reported.

Improving the odds to two-thirds or four-fifths would reduce the carbon allowance to just 150 Gt and 100 Gt, respectively — a two- or three-year lifeline at the current rate of emissions.

Keeping Paris temperature targets running will require cutting carbon dioxide₂ pollution by at least 40 percent by 2030, and completely eliminated by mid-century, the Intergovernmental Panel on Climate Change estimates.

Ironically, one of the great climate success stories of the past decade has inadvertently accelerated the pace of global warming, new data reveals.

A gradual decrease in the use of coal – a more carbon-intensive use of oil or gas – for energy production has slowed the increase in carbon emissions.

But it also reduced air pollution, which shields the Earth from the full force of the sun’s rays.

Particulate pollution from all sources limits warming by about half a degree Celsius, which means – in the short term at least – that more of that heat will reach the planet’s surface as the air gets cleaner.

Published in the peer reviewed journal Earth System Science DataThe new study is the first in a series of periodic assessments that will help close gaps between the IPCC’s reports, which have been issued on average every six years since 1988.

fatal heat

said co-author and scientist Maisa Rojas-Coradi, who is also a member of the study and Chile’s Minister of the Environment.

Co-author Valerie Masson-Delmotte, co-chair of the 2021 IGC report, said the new data should be a “wake-up call” ahead of the COP28 summit, even if there is evidence that the increase in greenhouse gases has slowed.

“The pace and scale of climate action is insufficient to stem the escalation of climate-related risks,” she said.

Researchers have also reported surprisingly large temperature increases over land areas – excluding the oceans – since 2000.

The study stated that “Earth’s average annual maximum temperatures have warmed by more than half a degree Celsius in the past 10 years (1.72 degrees Celsius above pre-industrial conditions) compared to the first decade of the millennium (1.22 degrees Celsius).”

Recent research has shown that longer and more intense heat waves will pose a threat to life and death in the coming decades across large swaths of South and Southeast Asia, along with equatorial regions of Africa and Latin America.

© 2023 AFP