Question

Lesson 3:  Climate Warning

Please explain why the urgent report by the Intergovernmental Panel on Climate Change, stating that it is imperative that atmospheric warming be held to 1.5 degrees Celsius. Please discuss in detail the many factors (notice I am emphasizing detail and many) that are contributing or will heavily contribute to this global issue.

Answer 1

Ans. There has been a delay in recognizing the existence and acceptance of global warming. This has led to enhanced global warming, leading to climate change. The concentration of carbon dioxide (CO2) has been increasing incessantly since the industrial revolution in the 1800s. Prior to industrial revolution the concentration of CO2 was about 260 ppm (parts per million), which increased to about 300 ppm following the industrial revolution. At present the concentration of CO2 is about 410 ppm. This is the highest recorded CO2 concentration in the history of mankind. The worst thing is that in spite of several conventions and conferences there has hardly been significant change in the CO2 concentration in most of the countries.

There has been an overall increase in average temperature of the earth. The warming, which begun since the industrial revolution, is taking place at the rate of 0.07oC per decade since the year 1880 as reported by the National Oceanic and Atmospheric Administration (NOAA). It also reported that with the subsequent increase in CO2 levels in the atmosphere the rate of temperature increase also was enhanced by about 0.13oC per decade. This will keep on increasing if the concentration of CO2 which is the main driver of global warming and climate change is not kept at bar. The warmest periods of the earth took place since 2005. In fact 2016 was considered the warmest year in several decades. In the earlier periods, there have been similar temperature surges, which have been followed by subsequent Ice Ages. However, the present CO2 concentration is so high that it can never lead to another Ice Age although some scientists are claiming we are in the middle of an Ice Age. The unforeseen melting of Green land and Arctic glaciers are the glaring example of this truth.

The increase in temperature is creating havoc world wide. The earth is witnessing extreme temperatures - extremely hot during the summer months along with heat waves and extremely cold during the winters. The temperature maximum and minimum are also increasing and decreasing significantly. There has been increasing the temperature of the water bodies as well. Water has a high specific heat due to which it absorbs heat slowly but retains it. This is why the ocean warming is leading to change in the atmospheric and oceanic circulation patterns. This in turn is affecting the climate and weather along with the shifting of seasons. There is uneven distribution of precipitation around the globe. Some areas are experiencing extreme rainfall leading to flooding conditions, whereas some areas are experiencing scarcity of rainfall leading to severe drought like conditions as are found in Syria. Along with the civil war, climate change has turned the drought into a severe one. Extreme temperatures during summer months are leading to drying up of the surface water leading to severe water scarcity. People have to cover long distances to get water supply. The condition is worsening with time in unison with lack of sustainable management of water resources.

The warming has a huge effect on the melting of glaciers. The glaciers are the biggest source of fresh water. Greenland is losing its ice mass at an unprecedented rate. The rate of melting is about 240 km3 per year. Since 1992 there has been a loss of about 3.8 trillion ice mass due to global warming. This is leading to mixing of fresh water with the saline and denser oceanic water. Usually heat distribution throughout the globe takes place through oceanic circulation, where the cold water from the polar regions and hot water from the equatorial regions are interchanged, thus maintaining the heat balance. Now when the fresh water concentration increases there is no upheaval or mixing of the water due to decreasing density difference (Normally sea water is more dense than fresh water). This will affect the circulation currents driving all weather patterns like wind systems. It has already been reported that the Atlantic Ocean current, the North Atlantic current is already slowing down due to the addition of the fresh water.

Moreover the thermal expansion of water bodies is leading to increase in sea level. The higher temperature of the water bodies is leading to increase in the number and intensity of the tropical cyclones. They are getting intensified day by day, most of the tropical cyclones are usually becoming intensified fast and causing devastation. This is bringing with it an additional storm surge and flooding of the coastal regions, inundation and water logging conditions of these areas, salination of the land field and agricultural fields, decreasing their fertility. So a temperature surge is affecting the environment terrifically. There is additional increase in different health hazards, like outbreak epidemics, pandemics due to sudden explosion in the population of undesirable pathogens. These pathogens are usually resistant to heat. There is decrease in productivity of the crops due to increased pest infestation, increased weeds, inhibition of the enzymes and hormones of the plants affecting germination.

So there is dire need to keep the temperature increase by 1.5oC as per the Intergovernmental Panel on Climate Change (IPCC). Global circulation models and other simulation models suggest there will be further increase of temperature in the coming years. This increase will make earth reaching the tipping point i.e., a point of no possible return. It means the changes thereafter will be irreversible and no one can save the mankind or the biodiversity from nature's fury. 1.5oC is the safest limit to the temperature increase, which should not be crossed.