Global warming: the situation is worse than believed ( on climate change/global warming)- Express Tribune

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IPCC report describes how human action had altered the global environment at an “unprecedented pace”

This has been an unusual summer for many parts of the world. High temperatures and droughts have affected most of the American west. There were widespread fires that burnt significant acreage in California, Oregon, and Washington states. There were also fires in Siberia. Heavy rains in India’s western states resulted in floods. There were also heavy rains in central China which caused destructive floods. The ice shield in the Antarctica began to melt at a faster rate than had been expected. The reason why these and other weather events were occurring was provided by the latest report issued by a high-powered panel of scientists that has been keeping a watch on the way global weather has been changing. The body, the Intergovernmental Panel on Climate Change (IPCC), issued its latest report on August 9, 2021, describing how human action had altered global environment at an “unprecedented pace”. The panel provided detailed account of how catastrophic consequences lie ahead unless nations around the globe rapidly and dramatically cut greenhouse gas emissions.

The panel had a number of historians who looked at deep past to see how climate has already affected the Earth and the people who live on the planet. Each of the past four decades has been successively warmer than the one that came before it, dating back to 1850. Mankind has warmed the climate at a rate without parallel since before the fall of the Roman Empire. According to the panel’s historians, to find a time when the level of carbon dioxide in the atmosphere changed this fast and this much, we will need to go back 66 million years. That was the time dinosaurs walked the Earth. Carbon dioxide in the atmosphere has risen to levels not experienced in 2 million years.

If action is not taken, the situation will worsen quickly. “The chances of unknown unknowns become increasingly large,” said Zeke Hausfather, director of climate and energy at the Breakthrough Institute and a member of the United Nations Panel. “We don’t have any great comparable analogues in the last 2 million years or so. It is hard for us to predict exactly what will happen to the Earth’s systems.” The evidence for mankind’s influence on the climate system, “once a fiercely debated topic, is now overwhelming”, says the report. What started as a scientific hypothesis has become “established fact”.  The report’s 42-page “summary for policymakers” uses the phrase “virtually certain” nearly a dozen times. The words “high confidence” are repeated more than a hundred times. The rate of sea-level rise, the retreat of ice sheets and glaciers, and the acidity of the oceans are all described as “unprecedented in the past several thousand years”. Even the certainty with which the panelists presented their findings has not caused the skeptics in the world of policymaking to stop resisting action. The effort by President Joe Biden has not persuaded the Republican opposition to accept his climate agenda.

Thirty years ago, the same panel had warned that mankind was causing a dangerous greenhouse effect and that if collective action was not taken to slow Earth’s warming, there could be “profound consequences” for people and nature alike. The latest report was compiled by 234 scientists who used 14,000 studies from around the globe to arrive at their findings. The report was released less than three months before the climate summit scheduled for November in Scotland. The UN Secretary General called the report’s conclusions “a code red for humanity” and said nations needed to find ways to limit global warming as much as possible. The report takes serious issue with the position taken by former President Trump and his political associates who dismissed global warming as a Chinese hoax perpetrated to set back American economic growth. It states that there is no remaining scientific doubt that human action was fueling climate change. That much is unequivocal. The only remaining uncertainty was that the world can gather the will to prevent darker times.

To help the policymakers along, the UN panel presented its suggestions for action in four areas. Heatwaves have become more frequent and hotter. Projections show that hot weather will increase in intensity through the 21st century even if global warming is held to 2.7 degrees Fahrenheit above preindustrial levels. Places such as Jacobabad in Pakistan’s Sindh province will become unlivable in a few years. Temperature rise is resulting in heavy downpours. The panel says in the report that heavy precipitation events have increased since the 1950s over most land areas around the world. With more warming, the experts predict, heavy precipitation events will intensify further, increasing by 7 per cent for every 1.7 degree Fahrenheit of warming. For South Asia, summer monsoons bring most of the sub-continent’s annual rainfall. These would become heavier and longer in duration, brining destructive floods. On the other end of the weather spectrum, droughts will become drier. Observations show that drought is increasing across substantial land areas. Several countries in Africa and the Middle East have seen reduction in agricultural output because of drying land. Scientists also see windier and rainier hurricanes. Major hurricanes rated Category 3 or higher have struck the United States, the Caribbean and Central America in recent years, seriously damaging coastal properties and displacing tens of thousands of people. The tropical Atlantic has seen several Category 5 storms in recent years. In Asia, hurricanes called by different names have also become more frequent and destructive.

What are the policy options for the countries in South Asia that result from the findings of the UN panel? Experts recognise that much of the global warming was caused by human action in the more developed parts of the world. However, poor and developing nations such as Pakistan are left to deal with a number of consequences. Among these the most significant is the faster melting of the glaciers in the mountain ranges that feed the rivers in the area. For some decades, the result will be destructive floods in the rivers as happened in the stretch of land in India’s Himalayan region. A small dam was destroyed by the fast runoff in the river and several people were killed. Such incidents are likely to occur with some frequency in the future.

Some years ago, the World Bank wrote a report on the medium-term impact of glacier melting in the Himalayan region from which the Indus system of rovers get their waters. The main conclusion of the work was that fast melting of glaciers would produce fast runoffs which would be followed by serious shortage of water in the rivers later this century. The Bank suggested a programme it called the Indus Cascades. This was to be series of 12 dams to be constructed on the Indus River. Rather than allow the fast-melting ice cover to produce water that would flow into the sea, the storages would save the water for programmed use. The under-construction Dasu dam being built by a Chinese company is one dam in this programme. The tree-growing project launched by the government of Imran Khan would also affect climate; Pakistan has allowed deforestation to procced at a rate at which a good part of the country would be turned into a desert. The main point of this analysis is that the situation – which the UN panel has suggested would affect much of the world – has already arrived in Pakistan.