[ad_1]
United States – Record CO2 concentration, extreme heat, retreating glaciers … The latest indicators on climate change show that it is urgent to act. According to the World Meteorological Organization (WMO), 2018 is likely to be the fourth hottest year since temperatures began in 1880. In this summer in the northern hemisphere, Europe, the United Western United States and Asia were hit by heat waves. [21] For example, in Portugal, Scandinavia, Japan and Algeria, record temperatures and gigantic fires were reported.
In the Arctic, the extent of pack ice remained well below average throughout the year and reached a record high in January. and February
Glaciers on the planet also fell for the 38th consecutive year. The concentration of the three main greenhouse gases – carbon dioxide (CO2), methane (CH4) and carbon dioxide (CO2) – is the country's highest peak, due to exceptional summer temperatures.
and nitrogen oxides (NOX) – have reached new heights in 2017 and are progressing again this year.
The concentration of CO2, a persistent gas for several centuries, was 405.5 parts per million (ppm) in 2017. The last time the Earth recorded a similar concentration, it was between 3 and 5 millions of years, according to the WMO. The temperature at the time was 2 to 3 ° C higher and the sea level was 10 to 20 meters higher than the current level.
Methane emissions, mainly related to the burning of fossil fuels and agricultural activities, have increased over the last decade. . Its concentration reached in 2017 a level equivalent to 257% of that recorded before the industrial revolution
. The rise in sea level, according to regions, was 20 cm, on average, in century XX. Currently, it increases by 3.3 mm per year and the phenomenon seems to accelerate. Sea level rose from 25% to 30% faster between 2004 and 2015 than between 1993 and 2004.
The melting ice of Greenland partly explains this increase. But Antarctica can become the main driver: in 2012, the white continent lost 76 billion tons of ice a year.
If warming were maintained at 1.5 ° C compared to the preindustrial era, sea level would rise from 26 to 77 centimeters by 2100, according to the predictions of l & # 39; UN. A higher temperature of 2 ° C would add 10 cm, thus affecting 10 million additional people.
Above all, in the long term, the icecaps of Antarctica and / or Greenland could be destabilized with a climate between +1.5 and 1.5 km. / 2 ° C warmer, increasing the sea level by several meters over the next centuries.
Global warming favors extreme weather events, including droughts and hot flashes. As of 20 November, WMO had recorded 70 tropical cyclones in 2018, compared with a historical average of 53.
According to some studies, the number of droughts, fires, floods and waterfalls Hurricanes related to climate change has doubled since 1990.
According to the Intergovernmental Panel on Climate Change (IPCC), heat waves of + 2ºC will occur in most regions and cyclone-related rainfall will be more intense
The losses badociated with natural disasters have reached $ 520 billion a year and are throwing 26 million people into poverty every year, according to the World Bank. 20% of the 8,688 threatened or endangered species have already been affected by climate change
Coral reefs have undergone mbadive bleaching in recent years and record mortality. scientists also point to a multiplicity of ocean heat events threatening marine ecosystems
[ad_2]
Source link
