Earth has long crossed the threshold of global warming dangers and catastrophic consequences loom; many scientists have warned. Some of their predictions have already taken place. People have experienced warmer summers, colder winters, extended monsoons, violent tornadoes, and storms all over the globe.
Other events of concern include environment experts finding microplastic in Antarctic ice for the first time. Heatwave in Antarctica that spiked temperature by 20 degrees for the first time.
An Earth.org report should alarm all. The report lists advancing permafrost meltdown in Arctic region, melting Greenland ice sheet at an unprecedented rate, hastening sixth mass extinction, increasing deforestation in the Amazon rainforest, warnings of air pollution worsening the spread of Covid-19.
The report says China has experienced its worst floods in decades. Methane levels have risen to their highest level on record. Canada’s last intact ice shelf has collapsed. A national park in the US recording the highest temperature ever recorded on Earth. 13 per cent of deaths in the EU linked to various forms of pollution. Population sizes of wildlife have experienced an average decline of 68 per cent since 1970 and record-breaking wildfires in California that have blocked out the sun. Worse, the report adds ‘these are just a fraction of the events’.
There’s hope for humans amid this depressing data. Control of short-lived climate pollutants - methane and ozone -- offers 50-per cent cut in rate of global warming, authors of a new study say.
Reducing CO2 emissions alone is not enough to prevent catastrophic global warming. The authors say, “Simultaneously reducing emissions of methane and, other often overlooked climate pollutants, we could cut the rate of global warming in half by 2050 and give the world a fighting chance.”
The study published earlier this week in the Proceedings of the National Academy of Sciences, is the first to assess the comparative impacts, through 2050, of reducing emissions of a broad range of climate pollutants versus targeting only carbon dioxide.
“Decarbonisation is crucial to meeting our long-term climate goals, but it's not enough,” says study co-author Drew Shindell, Nicholas Distinguished Professor of Earth Science at Duke University. “To slow warming in the near-term and reduce suffering from the ever-increasing heatwaves, droughts, superstorms and fires, we need to also reduce short-lived climate pollutants this decade.”
The new research shows focusing efforts exclusively on cutting carbon dioxide emissions, as most governments currently do, can no longer prevent global temperatures from rising above pre-industrial levels by 1.5 degree Celsius. Such a rise would substantially increase the risks of tipping points at which irreversible impacts will occur. Cutting carbon alone may not be enough to prevent temperatures from rising by 2°C, the study concludes.
“Our analysis shows climate pollutants such as methane, nitrous oxide, black carbon soot, low-level ozone and hydrofluorocarbons contribute almost as much to global warming as longer-lived CO2,” says Shindell. “Since most of them last only a short time in the atmosphere, cutting them will slow warming faster than any other mitigation strategy.”
It would also help us avoid a short-term warming ‘backlash’ that the Intergovernmental Panel on Climate Change (IPCC) has warned could occur by cutting fossil fuel emissions alone. Recent IPCC reports project that decarbonising the energy system and shifting to clean energy in isolation could perversely cause temperatures to rise for a while because, in addition to CO2, fossil fuel emissions contain sulphate aerosols, which act to cool the climate for a very short time -- from days to weeks -- before they dissipate.
The new study accounts for this effect and concludes that focusing only on reducing fossil fuel emissions could result in "weak, near-term warming" which could potentially cause temperatures to exceed the 1.5°C level by 2035 and the 2°C threshold by 2050.
In contrast, reducing both CO2 and other climate pollutants simultaneously would significantly improve our chance of remaining below the 1.50 C mark.
[Sudeep Sonawane, an India-based journalist, has worked in five countries in the Middle East and Asia. Email: [sudeep.sonawane@gmail.com]
Oman Observer is now on the WhatsApp channel. Click here
