In order to avoid catastrophic consequences of climate change, there is general agreement among the countries of the world to limit the rise in average surface temperature of earth compared to that of pre-industrial times by
1.5 °C to 2 °C
The figure the question is after comes from international climate negotiations rather than from any single scientific calculation, and it has been stated consistently for many years.
The agreed aim is to hold the rise in global average surface temperature to between 1.5 and 2 degrees Celsius above pre-industrial levels. The two degree limit was formally recognised in the Copenhagen Accord of 2009 and confirmed at Cancun in 2010; the Paris Agreement of 2015 restated it as holding warming well below 2 degrees while pursuing efforts to limit it to 1.5 degrees.
Pre-industrial is taken to mean the period before large scale burning of fossil fuels began, usually the second half of the nineteenth century, and it is the baseline against which the rise is measured.
The reasoning behind the threshold is that beyond about two degrees the risk of irreversible changes rises sharply - the loss of the Greenland and West Antarctic ice sheets, large scale sea level rise, widespread coral death, and the crossing of tipping points in ecosystems. The 1.5 degree figure was pressed particularly by small island states, for which two degrees of warming carries an existential threat from rising seas.
The range of 2.0 to 3.5 degrees describes a trajectory that current policies risk producing, but it is not a target anyone has agreed to; warming of that magnitude is precisely what the agreements exist to prevent. The ranges 0.5 to 1.0 and 0.25 to 0.5 degrees are below the warming that has already taken place, so they could not serve as limits.
Hence the agreed limit is a rise of 1.5 °C to 2 °C.
Similar Questions
Amongst the following Green House Gases (GHGs), whose Global Warming Potential (GWP) is considered as 1?
In the context of climate change which of the following observations are correct for 20th century with reference to 1750?
A. The global average surface temperature has increased by 0.6°C.
B. Greater increase in daytime temperature than night time has been observed.
C. Global average sea level rose 0.1-0.2 m largely due to thermal expansion.
D. The atmosphere concentration of Carbon dioxide (CO2) has increased by 31%.
E. Precipitation in the northern hemisphere has decreased by 1% per decade.
Choose the correct answer from the options given below:Which of the following Green House Gases has no natural source?
Given below are two statements :
Statement I : In many cases, both organisms and human infrastructure will not be able to move or adapt quickly enough to changing climate.
Statement II : Infectious diseases are likely to increase as a result of global warming.
In the light of the above statements, choose the most appropriate answer from the options given below :Full form of IPCC, a nodal agency in the context of climate change, is:
Given below are two statements
Statement I: Increased carbon dioxide concentration in the ambient atmosphere is likely to make the world's oceans less acidic.
Statement II: Increased carbon dioxide concentration in the ambient atmosphere is likely to impact the coral reefs adversely.
In light of the above statements, choose the correct answer from the options given below:Suppose the concentration of Carbon dioxide, a greenhouse gas responsible for climate change, is 400 ppm. What is its concentration in air in percentage terms?
How many National Missions of the Indian Government are there to address the problem of climate change?
In terms of total $CO_2$ emissions from a country, identify the correct sequence:
Which one of the following green house gases has the shortest residence time in the atmosphere?
Important Questions from Climate Change & Global Warming
Greenhouse gas, which is present in the highest quantity in the atmosphere, is
Which one of the following gases have higher Global Warming Potential?
Which of the following two sources of carbon is released?
A) Volcanic eruption
B) Combustion of fossil fuels
C) Landslide
D) Open mining
Choose the correct answer from the options given below:
Considering the global warming potential of CO 2as one, the global warming potential of CH 4has been estimated to be approximately :
Which of the following gas is not involved in the production of acid rain?
