Santa Barbara County, California, Fire Department via AP
The average temperature on Earth is now always 1 degree Celsius warmer than it was in the late 1800s, and this temperature will continue to rise towards the critical reference of 1.5 degrees Celsius over the next five years. years, according to a new report from the World Meteorological Organization.
Scientists warn humans must prevent the average annual global temperature from persisting at or above 1.5 degrees Celsius to avoid the most catastrophic and long-term effects of climate change. These include massive flooding, severe drought, and uncontrolled warming of the oceans that fuel tropical storms and result in massive deaths of marine species.
The new report from WMO, a United Nations agency, finds that global temperatures are accelerating towards 1.5 degrees Celsius of warming. The authors of the new report predict that there is a 44% chance that the average annual temperature on Earth will temporarily reach 1.5 degrees Celsius warming at some point in the next five years. This probability has doubled since last year.
“We are seeing an acceleration of change in our climate,” said Randall Cerveny, a climatologist at Arizona State University and rapporteur for the World Meteorological Organization who was not involved in the report.
Annual temperatures on Earth fluctuate with short-term climate cycles, which means that some years are much warmer than others, even though the overall trend line is steadily increasing. As climate change accelerates, it becomes increasingly likely that individual years will exceed 1.5 degrees Celsius of warming.
âWe had had some hopes that, with last year’s COVID scenario, perhaps the lack of travel [and] the lack of industry could act as a small brake, “says Cerveny.” But what we’re seeing, frankly, is not. “
Years of record heat provide a glimpse into the future. For example, 2020 was one of the hottest years on record. Global temperatures last year were about 1.2 degrees Celsius warmer than the late 1800s, according to the WMO.
Millions of people have suffered tremendously. The United States has seen a record number of billion dollar weather disasters, including hurricanes and wildfires. Widespread droughts, floods and heat waves have killed people on every continent except Antarctica.
The recent climatic catastrophes underline the extent to which a warming of a few degrees can have enormous effects. For example, during the last Ice Age, the Earth was only about 6 degrees Celsius cooler than it is now, on average. An increase of 1.5 degrees Celsius “is a very, very, very, very large number,” says Cerveny. “We have to be concerned about it.”
The goal of the Paris climate agreement is to keep the increase in global temperatures well below 2 degrees Celsius above pre-industrial levels, and ideally to try to limit warming to 1.5 degrees Celsius. These thresholds refer to the temperature on Earth over several years. To exceed 1.5 degrees Celsius of warming in a single year would not violate the Paris Agreement.
But with each passing year of increasing greenhouse gas emissions, it becomes more and more likely that humans are causing catastrophic warming. The report estimates that there is a 90% chance that one of the next five years will be the hottest year on record.
“This is yet another wake-up call that the world needs to accelerate commitments to reduce greenhouse gas emissions and achieve carbon neutrality,” WMO Secretary-General Petteri Taalas said in a statement. press release accompanying the report. the The United Nations warns that at the end of 2020, humans were on course to cause warming of more than 3 degrees Celsius by the end of the century.
If the United States keeps its new promises to reduce its greenhouse gas emissions, it would help limit global warming to some extent, although other countries, including China, are also expected to significantly reduce their emissions in the country. over the next 10 years.
In April, the Biden administration pledged to halve U.S. emissions by 2030 from 2005 levels. Most of those reductions are expected to come from electricity generation and transmission, including electricity. elimination of coal-fired power plants and the transition to electric cars and trucks. Congress is considering infrastructure legislation that could help advance these transitions.
Meanwhile, the fossil fuel industry is under increased pressure to invest in clean energy. A Dutch court on Wednesday ordered Shell to cut its carbon emissions faster, though the company plans to appeal the decision. And a small activist hedge fund has managed to place at least two new candidates on Exxon Mobil’s board, in a bid to push the company to take climate change more seriously.