What El Nino Means for the World’s Dangerous Climate Endpoints

The UN World Meteorological Organization (WMO) has confirmed: El Niño conditions are present arrived And they are expected to moderate to strong as they develop in the coming year. boy The warm phase of a natural fluctuation in the Earth’s climate system (its full name is El Niño-Southern Oscillation, or ENSO) that usually lasts a couple of years and occurs over a long-term trend. Human-driven global warming.

This year has already been proven warm. Widespread heat waves have contributed Hottest June on recordTemperatures were higher in the northeast Atlantic Up to 5°C warmer than normal In June, sea ice around Antarctica was 2.5 million square kilometers smaller than the annual average, the lowest ever. Since 1979.

This El Niño event is just beginning and is therefore only partially responsible for these recent highs. But with global average temperatures already high this year, El Nino could be stronger next year and 2024. Hottest year on record. El Niño can add up to 0.2 degrees Celsius to global temperatures.

The WMO now says there is Probably By 2027, Earth’s temperature will temporarily exceed 1.5 degrees Celsius. This is the temperature range that world leaders pledged to try to limit long-term warming when they signed the Paris Agreement in 2015. Beyond that, scientists predict. The impacts of climate change will increase rapidly.

Sea surface temperatures in the Pacific Ocean confirmed the arrival of El Niño in early June.
NOAA Climate.gov

These impacts may include triggering climate tipping points: spontaneous changes in the climate system that lock into catastrophic changes once critical warming levels have passed. An example West Antarctic Ice SheetIrreversible subsidence can be triggered when seawater, once heated, retreats back into the deep submarine basin where it sits. Up to 3 meters to global sea level rise. Tipping points can also prevent additional global warming by amplifying greenhouse gas emissions from natural sources.

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A recent study I conclude that many of these climate tipping points may lie beyond 1.5°C and that current warming cannot be ruled out even at 1.2°C. Could the global heat turbo-charged record by El Niño reach these tipping thresholds in the coming years?



Read more: Climate reference points could lock in unstoppable changes on the planet – how close are they?


Short-term heat extremes can disrupt systems like coral reefs and the Amazon rainforest. Some smaller ecosystems may also tip, but no more than the thousands of kilometers needed to count as a climatic tipping point. Retreat of sea ice Near the Antarctic Peninsula This suggests that parts of the West Antarctic ice sheet are also warming, even at current levels of warming. However, if El Niño causes the world to exceed 1.5°C, most scientists do not expect the world to reach climate tipping points.

Conclusion to reference points

Our estimates for climate tipping point ranges are based on what would happen if global warming remained at that level for many years. Therefore, a tipping threshold estimated at 1.5°C would mean that global temperatures would not have reached an average of 1.5°C per decade. Similarly, the Paris Agreement’s lower limit of 1.5°C will not be broken upon first contact – this Long-term average than the given year (or day) calculates

Given the wide ranges over which specific tipping points are estimated to lie, we cannot say with certainty when tipping is inevitable, and within that range tipping is more likely in every region of warming. Some systems, such as ice sheets, are slow to respond to global warming and may be a the window It will temporarily exceed the critical threshold for a few decades. This gives the system a chance to bring warming back down to a new level before it warrants a move to a new level.

Some commentators worry that recent temperatures and sea ice may be the result of extremes The ends are approaching. Because some complex systems „Flickr” When stressed, they will briefly jump to a new position and return again before they are permanently tilted. It is even suggested that there may be recent peaks Evidence Tipping is Already underway.

Glitter before dipping Possible, but systems like Antarctic sea ice or Ocean currents Not known Act this way.

Sunset through the ice floes hanging on the ice shelf around Antarctica.
Antarctic ice reflects sunlight back into space, cooling the Earth.
Carl Jackson/Alamy Stock Photo

Rather than approaching an unexpected tipping point, the dramatic extremes in temperature and sea ice extent are explained as natural variations on top of long-term warming. In other words, they sit within a natural range that is rapidly moving upward as a result of global warming. emissions Aerosols reflect sunlight from a ship And in 2020 the new norms fell sharply. These prevented the small-scale warming that is now starting to reappear.

Temperature records broken during an El Niño event are a sign of global warming, and this is long-term warming that will eventually trigger climate tipping points, especially when the global average exceeds 1.5°C. An El Niño event can help disrupt some systems if they are small or respond quickly.

For example, when average warming reaches about 1.5°C, a future strong El Niño will temporarily push global average temperatures to 1.7°C, so some coral reefs will begin to die before a cooler La Niña arrives. The same could happen if the thresholds for coral reefs fall below their estimated range during this El Niño. However, the low-end climate is the tipping point limits Chances are low. For other systems that respond slowly to warming, such as ice sheets, a subsequent La Niña should (temporarily) balance things out.

Therefore, it is unlikely, but not impossible, that this new El Niño event will directly trigger climate tipping points. Conversely, upcoming El Niño events combined with human-driven global warming will continue to break temperature records, and the likelihood of crossing tipping points will continue to grow as long-term warming continues.

Increasing global warming through continued burning of fossil fuels will create future El Niño events And more serious. Modeling suggests this Can already happen. A further push, if necessary, is to reduce greenhouse gas emissions to minimize their damage.

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