To summarize what is happening in the world today I thought I would point out some of the effects of this climate change we are in the middle of. WG1 has written a ”Summary for policymakers”
and here are the points of this summary:
- Each of the last three decades, the surface of the earth has been warmer than all earlier decades, since 1850. In the northern hemisphere, the period 1983-2012 has probably been the warmest 30-year period in the last 1,400 years.
- The ice on Greenland and Antarctic has decreased in volume over the past two decades. Glaciers have continued to shrink. Arctic sea ice and snow cover in the Northern Hemisphere are continuing to decline.
- Since the mid 1800s the sea level has been rising faster then the average rate over the last two millennium. Between 1901 and 2010, the average sea level rose 19 cm (17-21 cm) a year.
- The concentration of greenhouse gases in the atmosphere have risen to levels higher then the last 800 000 years. The concentration of carbon dioxide has increased by 40 percent since pre-industrial times.
- Continued emissions of greenhouse gases will cause further warming and changes in all climate system components. Limiting climate change will require significant and sustained reductions in greenhouse gases.
- The oceans will be warmer and the heat will be transferred from shallow water to deep ocean layers and influence ocean circulation.
- The average sea level will continue to rise and all scenarios in the report shows that the rate will increase compared with the rate at which sea levels have risen during the period between 1971 to 2010. The reason is increased warming of the oceans and melting of glaciers and ice sheets.