5 Takeaways from the UN Climate Report


The Intergovernmental Panel on Climate Change, a scientific body convened by the United Nations on Monday, has released an important new report concluding that the world cannot avoid some of the devastating effects of climate change, but there is still a narrow window to prevent the havoc from spreading. worse.

Based on an analysis of more than 14,000 studies, the report is the clearest and most comprehensive summary of the physical science of climate change yet. It reveals what the climate was like in the past, how it is now, and what it will be like for decades to come. And it shows how people can affect the future climate by actions they take now or don’t take to reduce their emissions of carbon dioxide and other heat-trapping gases.

Here are five takeaways report:

This report is the sixth assessment of climate science by the UN group, and unlike previous reports, this report removes any doubt as to who or what is responsible for global warming. “Human influence is certain to warm the atmosphere, ocean and land,” the report says in its first finding.

Observed increases in atmospheric carbon dioxide since 1750 can be directly attributed to human activities, such as the burning of coal, oil and other fossil fuels, in large part as the world industrializes. These emissions have increased greatly over time and continue today as the world gets warmer. And there are effects felt in every region. of the world.

One of the reasons the report concludes that humans are responsible for global warming is that climate research has improved drastically even in the eight years since then. previous UN report published.

There is much more observational data – temperature measurements and other data from instruments on land, oceans and space – that reduces uncertainty about what is going on. The improvement is particularly noticeable in parts of the world that are less affluent and historically have little capacity to collect climate data.

Computer models that simulate the climate have also greatly improved, and there is more computing power to run these simulations faster so they can be repeated over and over. These improvements, along with the ability to add more and better data to models, give scientists more confidence that their models accurately predict the future climate.

Over the past decade, great strides have been made in association research aimed at examining possible links between climate change and certain extreme events, such as heat waves and heavy rains. Research teams can now quickly analyze an event and determine whether warming is more or less likely to occur, adding to general confidence in the nature of climate change.

The Earth has warmed by about 1.1 degrees Celsius (about 2 degrees Fahrenheit) since the 19th century. The report concludes that humans are releasing so much carbon dioxide and other greenhouse gases into the atmosphere that even if countries take urgent steps today to drastically reduce emissions, this warming will continue until at least the middle of the century.

This means that some of the obvious impacts the world is seeing right now – such as extreme droughts, severe heat waves and devastating showers and flooding – will continue to worsen for at least the next 30 years.

Some other effects will last much longer. The massive ice sheets in Greenland and West Antarctica will continue to melt, at least until the end of the century. Global sea level will continue to rise for at least 2000 years.

The report found that some changes were greater than ever before compared to previous time periods ranging from centuries to thousands of years.

carbon dioxide concentration in the atmospherefor example, it is larger than at any time in the last two million years. The extent of late summer sea ice in the Arctic is lower than it has ever been in the past 1,000 years.

But the report also revealed that changes are happening faster now than even in the much more recent past. The rate of sea level rise has roughly doubled since 2006. Each of the last forty years has been consistently warmer than the previous one. Heat waves on land have gotten significantly warmer since 1950, and sea ​​heat waves – extreme heat bursts in the ocean that can kill marine life – their frequency has doubled in the last four decades.

The report outlined five climate futures in which people are taking various steps to reduce the emissions that cause warming. Beneath all this, the world will reach 1.5 degrees by 2040 or less, which is more ambitious than the targets set by the Paris climate change agreement in 2015.

According to many of the scenarios discussed in the report, warming will continue beyond 2040 for the remainder of the century. In the worst cases where the world does little to reduce emissions, by 2100 temperatures could be 3 to 6 degrees Celsius (5.5 to 11 degrees Fahrenheit) above pre-industrial levels. This would have disastrous consequences.

But the report shows that starting now, aggressive, rapid and widespread emissions cuts could limit warming beyond 2050. In the most optimistic scenario, reaching “net zero” emissions could return warming to just under 1.5 degrees Celsius in the second half of the year. Century.

Such a scenario would be a gigantic and expensive undertaking for the world. It will also require a level of political will that most governments have not been able to muster so far.


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