Wednesday, 22 March 2017

Present Biggest Issue : GLOBAL WARMING


Global warming means the change of surface temperature from 1880 to 2016. Global warming and climate change are terms for the observed century scale rise 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 warming. Many of the observed changes since the 1950’s are unprecedented over tens to thousands of years.
 In 2014, the Intergovernmental Panel on Climate Change (IPCC) fifth assessment report concluded that, “it is extremely likely that human influence has been that dominant cause of the observed warming since the mid 20th century”. The most harmful human influence has been emission of green house gases- such as carbon di oxide, methane, nitrous oxide and CFC. Our activities have led to carbon di oxide concentrations above levels not seen in hundreds of thousands of years. Climate model projections summarized in their report that during the 21st century the temperature of the global surface has increases further 0.3 degree C to 1.7 degree C (0.5F to 3.1F) for their lowest emissions scenario and 2.6 degree C to 4.8degree C(4.7F to 8.6F) for the highest emissions scenario. These researches have been recognized by the national science academics of the major industrialized nations and are not disputed by any scientific board of national or international standing.
Future climate change and associate impacts will differ from region to region around the globe. Anticipated effects include warming the temperature of the earth, rising the sea water levels, precipitation and expansion of deserts in the subtropics. Global warming expected to be greater over land than over the oceans and greatest in the Arctic of glaciers, permafrost and sea ice.
Possible societal responses to global warming include mitigation by emissions reduction, adaptation to its effects, building systems resilient to its effects, and possible future climate engineering. Most countries are parties to the United Nation Framework Convention on Climate Change (UNFCCC), whose ultimate objective is to prevent dangerous anthropogenic climate change. Parties to the United Nation Framework Convention on Climate Change have agreed that deeps cuts in emissions are required and that global warming should be limited to well below 2.0 degree C (3.6F) relative to preindustrial levels with efforts made to limit warming to 1.5 degree C(2.7F).
Public reaction to global warming and concern about its effects are also increasing. A global 2015 few research center reports shown a medium of 54% consider it “a very serious problem”.
Effects of Global Warming: There are two types of effects of global warming-
a)      Present time effects of global warming.
b)      Future time effects of global warming.
 The effects of global warming are the environmental and social changes caused (directly and indirectly) by human emissions of green house gases. There is a scientific consensus that climate change is occurring, and that humans activities are the primary driver. Many impacts of climate change have already been observed, including glacier retreat, changes in the timing of seasonal events, and changes in agricultural productivity.

Future effects of climate changes will vary depending or climate change policies and social development. The two main policies to address climate change are reducing human green house gas emissions (climate change mitigation) and adapting to the impacts of climate change. Geongineering  is another policy option.

No comments:

Post a Comment