Is Global Warming Natural or Anthropogenic?

Dr. Romio Khangemba *

The topic of Global Warming has always been a controversial issue among the scientific community worldwide right from day one when the first Agreement was signed in Kyoto, Japan in 1997. There are mainly two scientific communities who argue for and against the topic in the world. One group support the theory of human-caused global warming as the dominant factors for the changing climate worldwide and another group which reject the theory.

The first group of climate scientists/authors represented by Intergovernmental Panel on Climate Change (IPCC) has been the driving force to bring a consensus on the issue of global warming among 195 member nations in September, 2015 in the famous 21st Conference of Parties, (COP21) in Paris. The scientific reports of the IPCC which is known as the Assessment Reports published by IPCC after every 5/6 years has played an important role in bringing a consensus among the member nations in the Paris Agreement.

The second group of scientific community although confined within America, got momentum for further protest against the Kyoto Climate Agreement when the then U.S. Vice President Al Gore started publicity campaigns in 2007 claiming “consensus” of scientists in favour of the hypothesis of human-caused global warming.

Further, the issue was escalated by Donald Trump in the election campaign of U.S.A. President in 2016. Here, it may be noted that altogether 31,487 University Science degree holders including 9029 PhDs in America signed the petition against the Paris Agreement. Surprisingly, the petition project was also supported and endorsed by Frederick Seitz past president, of National Academy of Sciences, U.S.A. Taking advantage of the situation, Donald Trump used the card of Paris Agreement in the election campaign against the democratic candidate Barrack Obama.

He claimed that the ongoing political and media portrayal of global warming and climate change is totally false. The issue of global warming is a hoax and therefore the signing of Barrack Obama in the Paris Agreement, is a blunder which would result in losing 2.7 million jobs in U.S.A. thereby jeopardising the welfare and economic security of American citizens. The propaganda was so effective that Donald Trump easily got through the election and became the 45th President of America on 20th January, 2017 with thumping majority.

The followings are some of the points put forward by the scientific community who are in opposition to the Paris and other similar Agreements.

According to the scientific community who oppose the Kyoto and Paris climate Agreement, the present climate change is natural and it is not manmade as claimed by IPCC. The 0.8C increase in the average global temperature over the last 100 years is entirely consistent with well established long term natural climate trends which varied within a range of 3 degree centigrade. There is no scientific proof to define the current global warming is caused by anthropogenic greenhouse gases emission.

These scientists are instead convinced that the human-caused global warming hypothesis is without scientific validity and that government action on the basis of this hypothesis would unnecessarily and counterproductively damage both human prosperity and the natural environment of the Earth. CO2 emission by man throughout human history constitute less than 0.00022 percent of the total naturally emitted from the mantle of the earth during geological history.

To them, temperatures of the Earth have often been warmer than now with higher CO2 levels throughout the Earth’s history. The phenomenon of rising sea level is not new. It has been going on since ice age some 10,000 years ago. It is myth that receding glaciers are proof of global warming as glaciers have been receding and growing cyclically for many centuries.

There is no scientific or statistical evidence whatsoever that global warming will cause more storms and extreme weather events. It is myth that CO2 is the most common greenhouse gas that is responsible for the present global warming because CO2 constitutes mere 0.037% of the total 3% greenhouse gases in the atmosphere. It is rather the sun which is responsible for the greater share of climate change.

To them, increase in atmospheric content of CO2 and relative increase in global warming is more beneficial to human beings than cold climate. Therefore, the proposed limits on greenhouse gases emissions by the IPCC would harm the environment, hinder the advancement of science and technology, and damage the health and welfare of mankind.

On the other hand, the other group of scientists is represented by Intergovernmental Panel on Climate Change (IPCC). As we understand, IPCC is the only international body established for assessment of scientific information relevant to human induced climate change, its impact and options for adaptation and mitigation under the supervision of World Meteorological Organisation (WMO) and United Nations Environment Programme (UNEP).

It is also endorsed by the United Nations (UN). Although, IPCC does not carry out its own research, it operates on the basis of scientific papers and independently documented results from other scientific bodies worldwide. For example, the Fifth Assessment Report (AR5) of IPCC published in 2013-2014 was written by 830 climate authors/ experts from 85 countries selected from 3000 nominations over a period of 6 years.

Therefore, its Assessment Reports are regarded as the most authentic and scientific ones by the member nations. The Assessment Reports of the IPCC therefore are endorsed by more than 197 international scientific organisations including National Science Academies from 80 countries.

The followings are some of the points put forward by IPCC in favour of human-caused global warming; the dominant factors for present climate change.

According to IPCC’s Fifth Assessment Report (AR5), Earth’s climate is warming. Since the 1950s, the rate of global warming has been unprecedented compared to the previous decades and millennia. The average increase in the Earth’s temperature during the period has been 0.85 degrees Centigrade. IPCC finds the increase in the global temperature with 95% scientific certainty due to excessive release of greenhouse gases mainly CO2 by man during the period.

Secondly, IPCC have observed that global sea levels have risen faster than at any time during the previous two millennia. Thirdly, the Asia region as a whole have been observed the most weather and climate related disasters in the world between 2000 and 2017 due the changing behaviour of Asiatic Monsoon caused by changing rainfall, melting snow or ice worldwide.

IPCC have also observed receding of Himalayan Glaciers faster than in any part of the world. It also has observed that the Greenland and Antarctic ice sheets have been losing mass in the last two decades and that of the Arctic sea and Northern Hemisphere as well. Unequivocal Warming of the atmosphere and ocean system has been observed and sea level change is unprecedented since 1950.

It is extremely likely that anthropogenic influence has been the dominant cause of all the above observed warming since 1950. Lastly, IPCC have pointed out that the longer we wait to reduce our emissions, the more expensive it will become.

Projections by IPCC

o Further warming will continue if emissions of greenhouse gases continue.
o The global surface temperature increase by the end of the 21st century is likely to exceed 1.5 degree Celsius above the preindustrial level and is likely to exceed 2.0 degree Celsius for many scenarios.
o The oceans will continue to warm with heat extending to the deep ocean, affecting circulation patterns.
o The global water cycle will change with increases in disparity between wet and dry regions as well as wet and dry seasons, with some regional exceptions
o Further decreases are very likely in Arctic sea ice cover, Northern Hemisphere spring snow cover and global glacier volume.
o Global mean sea level will continue to rise at a rate very likely to exceed the rate of the past four decades.
o Increase in the rate of global CO2 production will increase uptake of CO2 by the oceans thereby increasing ocean acidification.
o Future surface temperature will be largely determined by cumulative CO2 which means climate change will continue even if CO2 emissions are stopped.