As the southern hemisphere summer of 2023/24 approaches, climate scientists are issuing dire warnings about the consequences for the planet of the growing climate crisis.
This comes after a Northern Hemisphere summer that produced scorching heat waves across Eurasia and North America, accompanied by devastating wildfires.
Andrew King, a climate scientist at the University of Melbourne, saidnatureThere is a good chance of record high temperatures, at least on the global average, and some particularly extreme events in some parts of the world.
One of the clearest indicators was the announcement on December 7 by the Copernicus Climate Change Service (C3S) that 2023 was the hottest year on record, two days warmer than in pre-industrial times. Scientists predict that 2024 may be even hotter.
As long as greenhouse gas concentrations continue to rise, we cannot expect a different outcome than this year. Temperatures will continue to rise, as will the impacts of heat waves and droughts. Carlo Buontempo, director of C3S, said reaching net zero emissions as quickly as possible is an effective way to manage climate risks.
Strong El Niño events in the Pacific and the Indian Ocean Dipole are exacerbating runaway global warming. These are natural weather patterns that control Earth’s weather systems, but combined with global warming can have dire consequences.
The Australian Bureau of Meteorology (BOM) declared the current El Niño event in September. This is often associated with heat waves. This follows the past three years of Rania weather systems, which typically produce wet and cool weather. This masks the impact of global warming to some extent.
King tells us the full effects of climate change are being felt rightnature.
El Niño and Rania are part of the El Niño-Southern Oscillation (ENSO) weather pattern, which has a strong influence on the world’s climate. They are based on the temperature difference between the central and eastern Pacific Ocean.
In August, the BOM reported that the Indian Ocean Dipole (IOD) had become positive. This is related to the hot and dry weather on the Australian continent. The IOD is the sea temperature difference between the west pole of the Arabian Sea and the east pole of the Indian Ocean south of Indonesia.
Together, these two climate systems caused Australia’s very severe bushfire season in 2019-20, with devastating impacts on rural communities and the environment.
In East Africa, the combination of two weather systems is expected to cause extreme rainfall and flooding. Above-average spring rainfall is expected in southern Africa, followed by warm and dry weather in the summer.
In South America, El Niño is expected to bring excess rainfall and flooding, particularly in Peru and Ecuador, but also very dry weather and drought in the Amazon and the Northeast.
One feature of the Northern Hemisphere that accompanies unprecedented summer heatwaves is the heat dome. This is due to the large land mass that circulates areas of warm, dry air that prevents the movement of low-pressure systems that bring cooler weather. This is not expected to occur in the Southern Hemisphere because the ratio of ocean to land is much higher (the Southern Hemisphere is 80% water compared to 60% in the Northern Hemisphere).
However, many indicators around the world suggest that the Southern Hemisphere may experience unprecedented summer heatwaves.
One of the most important factors is ocean warming, which is causing severe shrinkage of Antarctic ice. The world’s oceans cover more than 70% of the globe and, because water has a very high heat capacity, act as a radiator for warming in much of the world. According to the National Aeronautics and Space Administration (NASA), 90% of global warming has been absorbed by the surface waters of the first few meters.
In April, the National Oceanic and Atmospheric Administration (NOAA) reported that ocean temperatures had reached unprecedented highs. Data collected by satellites and ocean buoys show that the average temperature at the ocean surface is 21.1CSince early April; the previous record was 21C Set in 2016. Even small differences across all the world’s oceans can lead to significant increases in global warming.
Professor Matthew England, a climate scientist at the University of New South Wales, said the current trajectory looked set to break the record, smashing previous recordsprotector.
Rising ocean temperatures are causing sea levels to rise due to thermal expansion, coral bleaching, accelerated melting of Earth’s major ice caps, intensified hurricanes, and changes in ocean health and biochemistry.
Comment by Kevin Trenberth, Distinguished Scholar, National Center for Atmospheric Research, Oakland, January 2022dialogueRecord levels of ocean heat are having a major impact, noting that all oceans are warming, with the Atlantic and Southern Oceans around Antarctica warming the most. This is a concern for Antarctica, where the icy heat of the Southern Ocean could spread beneath the Antarctic ice shelves, thinning them and causing giant icebergs to calve. Ocean warming is also an issue with rising sea levels.
Scientists are particularly alarmed by the unprecedented warming at the poles. In winter, sea ice around Antarctica reaches record lows, leading scientists to predict feedback loops.
Ariaan Purich, a climate scientist at Australia’s Monash University, said large areas of the Southern Ocean that would normally still be covered by sea ice in October are no longer there.nature.
This leaves less sea ice to reflect heat back into space, leaving dark oceans to absorb the heat. That then warms the surface, and it melts more sea ice, so we get this positive feedback, Prich continued.
Global warming is more severe at the poles than elsewhere on Earth, a process known as polar amplification. Antarctica is warming three times faster than the rest of the planet.
A study by physical geographer Kyle Clem and his team at the School of Geography at Victoria University of Wellington was published in June 2020natural climate changeAntarctic warming has reached record highs over the past three decades. They found that the last 30 years from 1989 to 2018 experienced the largest 30-year average annual warming trend on record, which was 0.61 0.34 C 101 (95% confidence interval, CI), more than three times the global average rate.
West Antarctic sea ice is of particular concern because if it collapses, global sea levels could rise by several meters. The ice sheet is vast, containing 2.2 million square kilometers of ice. Over the past 50 years, temperatures have increased by more than 0.1 degrees Celsius per decade.
Important research, led by ocean modeler Kaitlin Naughten and her team from the British Antarctic Survey in Cambridge, was published in October 2023natural climate change,and named,The inevitable future increase in melting of the West Antarctic Ice Shelf in the twenty-first century. A number of possible scenarios were simulated to predict the melting of the ice shelf, including global warming stabilizing towards the Paris Agreement targets of 1.5°C and 2°C. .
All these simulations suggest that the melting of West Antarctic sea ice may have reached a point of no return. This is a very alarming result because complete melting of the ice sheet would cause sea levels to rise by 5m. Internationally, this would flood low-lying islands and low-lying coastal areas, destroying countless communities.
Nortonet al.state, our simulations present a sobering prospect of the Amundsen Sea [a section of the West Antarctic Sea]. Severe ocean warming and ice shelf melting are projected for all future climate scenarios, including ambitious ones considered unrealistic. The baseline for rapid ocean warming and consequent sea level rise in the twenty-first century appears to have been set. This warming is primarily due to the acceleration of the Amundsen Undercurrent, which transports warm CDW (circumpolar deep water) onto the continental shelf. Basal melting is increasing across all ice shelves in the Amundsen Sea, including areas that provide critical support for grounded ice sheets.
The CDW is a combination of ocean currents at a depth of about 500 m, including those from the Atlantic, Pacific, and Indian oceans.
It looks like we’ve lost control of the melting of the West Antarctic ice sheet. Norton tells us we needed to take action on climate change decades ago if we wanted to preserve its historic state.science.
David Karolyi, an atmospheric scientist at the University of Melbourne and a member of the Intergovernmental Panel on Climate Change, predicts that the situation will worsen next year.
Karoli told us that we know El Niño’s impact on temperatures occurs a year after the event.nature.
Important findings from climate scientists underscore that we are on the edge of a cliff and that the world’s climate is entering uncharted territory, with dire consequences for humanity’s future. Governments around the world have done nothing to curb the production of greenhouse gases due to their complete ownership of big business, including the fossil fuel industry.
Sultan Al Jaber, Chairman of the recent climate summit COP 28, Minister of Industry and Advanced Technology of the United Arab Emirates and Head of Abu Dhabi National Oil Company, spoke on behalf of all the dignitaries attending the meeting when he claimed: “Outside There is no science, or any scenario, that phasing out fossil fuels will achieve 1.5 degrees Celsius (the recommendation to limit rising global warming).
This underlines that the only way out of this impasse is for the working class, in alliance with principled scientists, to fight for a socialist reorganization of society that can meet its energy needs without destroying the planet’s environment.
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