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- Written by: Glenn and Rick
- Category: Global Heating
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More than 90% of the heat trapped by humanity’s greenhouse gas emissions has been absorbed by the seas, with just a few per cent heating the air, land and ice caps respectively. The vast amount of energy being added to the oceans drives sea-level rise and enables hurricanes and typhoons to become more intense. Much of the heat has been stored in the ocean depths but measurements here only began in recent decades and existing estimates of the total heat the oceans have absorbed stretch back only to about 1950. The new work extends that back to 1871. Scientists have said that understanding past changes in ocean heat was critical for predicting the future impact of climate change. A Guardian calculation found the average heating across that 150-year period was equivalent to about 1.5 Hiroshima-size atomic bombs per second. But the heating has accelerated over that time as carbon emissions have risen, and was now the equivalent of between three and six atomic bombs per second. obviously, we are putting a lot of excess energy into the climate system and a lot of that ends up in the ocean. There is no doubt.” The total heat taken up by the oceans over the past 150 years was about 1,000 times the annual energy use of the entire global population. The research has been published in the journal Proceedings of the National Academy of Sciences and combined measurements of the surface temperature of the ocean since 1871 with computer models of ocean circulation. Rising sea level has been among the most dangerous long-term impacts of climate change, threatening billions of people living in coastal cities, and estimating future rises is vital in preparing defences. Some of the rise comes from the melting of land-bound ice in Greenland and elsewhere, but another major factor has been the physical expansion of water as it gets warmer https://www.edie.net/news/9/
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- Written by: Glenn and Rick
- Category: Global Heating
- Hits: 143
Extreme heat is exposing people in big cities to potentially deadly temperatures three times more often than it did in the 1980s, according to a new analysis. Much of that increase is concentrated in South Asia, Africa, and the Middle East. Though climate change is a factor, heat stress is being exacerbated by poverty and the explosive population growth of cities in parts of the developing world. The findings show policymakers need to adapt cities to extreme conditions, says Deepti Singh, a climate scientist at Washington State University, Vancouver, who studies heat waves and was not involved in the research. “Every single year we have so many deaths associated with extreme heat that to a large extent are avoidable.” Some parts of the globe are already crossing temperature and humidity thresholds that can kill people in hours. In coastal India, West Africa, and the Persian Gulf, for example, heat waves reach deadly conditions every year, on average. And the pain is increasingly felt in cities, where populations are growing and heat-absorbing concrete and pavement compounds the problem. But it has been a challenge to gauge the full impact these rising temperatures are having on urban dwellers around the world, says Cascade Tuholske, a geographer and postdoctoral scientist at Columbia University who led the research. Some parts of the world have spotty coverage from reliable weather stations, whereas satellite measurements of heat only cover larger stretches of land, obscuring conditions in individual cities.To work around those gaps, Tuholske and fellow U.S. researchers turned to a data set recently developed by scientists at the University of California, Santa Barbara. The trove combines the global reach of satellites with the detailed observations of weather stations to create a portrait of daily maximum temperatures across the globe at a scale down to 25 square kilometers—an area about half the size of Manhattan. India alone accounts for more than half of the world’s increase in urban heat exposure—more than the other top 24 countries combined, the team reports today in the Proceedings of the National Academy of Sciences. The country is home to four cities in the top 10: New Delhi, Kolkata, Mumbai, and Chennai. Europe and North America have no cities in the top 50. An interactive mapshows hot spots around the world. https://www.science.org/
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