25-02-2015, 10:08 AM
13-10-2017, 03:45 PM
Global warming also known as climate change. It is the observed increase in the century's scale in the average temperature of the Earth's climate system and its related effects. Multiple lines of scientific evidence show that the climate system is heating up. Many of the changes observed since the 1950s are unprecedented in the record of instrumental temperature dating back to the mid-nineteenth century and in the paleoclimatic proxy records that cover thousands of years.
In 2013, the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) concluded that "it is extremely likely that human influence has been the dominant cause of warming observed since the mid-twentieth century." The greatest human influence has been the emission of greenhouse gases such as carbon dioxide, methane and nitrous oxide. The climate model projections summarized in the report indicated that during the 21st century global surface temperature is likely to increase between 0.3 and 1.7 ° C (0.5 to 3.1 ° F) in the lower emissions scenario, and between 2.6 and 4.8 ° C (4.7 to 8.6 ° F) in the highest emissions scenario. These findings have been recognized by the national science academies of the major industrialized nations and are not discussed by any scientific body of national or international prestige.
Future climate change and associated impacts will vary from one region to another in the world. The announced effects include increasing global temperatures, rising sea levels, changing precipitation, and expanding deserts in the subtropics. Warming is expected to be greater over land than over oceans and the largest in the Arctic, with continued withdrawal of glaciers, permafrost, and sea ice. Other likely changes include more frequent extreme weather events, such as heat waves, droughts, heavy rains with floods and heavy snowfalls; Oceanic acidification; and extinctions of species due to changes in temperature regimes. Significant effects on humans include the threat to food security from declining crop yields and the abandonment of populated areas due to sea level rise. Because the climate system has great "inertia" and greenhouse gases will remain in the atmosphere for a long time, many of these effects will persist not only for decades or centuries, but for tens of thousands of years to come.
Possible social responses to global warming include mitigation of emissions reductions, adaptation to their effects, construction of systems resistant to their effects and possible future climate engineering. Most countries are parties to the United Nations Framework Convention on Climate Change (UNFCCC), whose ultimate goal is to prevent dangerous anthropogenic climate change. Parties to the UNFCCC agreed that there is a need for deep cuts in emissions and that global warming should be limited to far below 2.0 ° C (3.6 ° F) compared to pre-industrial levels, with efforts to limit global warming at 1.5 ° C (2.7 F).
Public reactions to global warming and concern about its effects are also increasing. A report from the 2015 Pew Research Center showed that a median of 54% of all respondents asked that it was a "very serious problem." There are significant regional differences between the Americans and Chinese (whose economies are responsible for the largest annual CO2 emissions) among the least interested.
In 2013, the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) concluded that "it is extremely likely that human influence has been the dominant cause of warming observed since the mid-twentieth century." The greatest human influence has been the emission of greenhouse gases such as carbon dioxide, methane and nitrous oxide. The climate model projections summarized in the report indicated that during the 21st century global surface temperature is likely to increase between 0.3 and 1.7 ° C (0.5 to 3.1 ° F) in the lower emissions scenario, and between 2.6 and 4.8 ° C (4.7 to 8.6 ° F) in the highest emissions scenario. These findings have been recognized by the national science academies of the major industrialized nations and are not discussed by any scientific body of national or international prestige.
Future climate change and associated impacts will vary from one region to another in the world. The announced effects include increasing global temperatures, rising sea levels, changing precipitation, and expanding deserts in the subtropics. Warming is expected to be greater over land than over oceans and the largest in the Arctic, with continued withdrawal of glaciers, permafrost, and sea ice. Other likely changes include more frequent extreme weather events, such as heat waves, droughts, heavy rains with floods and heavy snowfalls; Oceanic acidification; and extinctions of species due to changes in temperature regimes. Significant effects on humans include the threat to food security from declining crop yields and the abandonment of populated areas due to sea level rise. Because the climate system has great "inertia" and greenhouse gases will remain in the atmosphere for a long time, many of these effects will persist not only for decades or centuries, but for tens of thousands of years to come.
Possible social responses to global warming include mitigation of emissions reductions, adaptation to their effects, construction of systems resistant to their effects and possible future climate engineering. Most countries are parties to the United Nations Framework Convention on Climate Change (UNFCCC), whose ultimate goal is to prevent dangerous anthropogenic climate change. Parties to the UNFCCC agreed that there is a need for deep cuts in emissions and that global warming should be limited to far below 2.0 ° C (3.6 ° F) compared to pre-industrial levels, with efforts to limit global warming at 1.5 ° C (2.7 F).
Public reactions to global warming and concern about its effects are also increasing. A report from the 2015 Pew Research Center showed that a median of 54% of all respondents asked that it was a "very serious problem." There are significant regional differences between the Americans and Chinese (whose economies are responsible for the largest annual CO2 emissions) among the least interested.