Turn Down the Heat

Climate Change – a basic primer for the lay person

We  have learnt in school about the Ice Age and the Interglacials – periods over which the earth witnessed massive changes in the climate and environment leading to the extinction of several species. What distinguishes the present discussions on climate change is the fact that there have been major advances in science- scientific analyses from observations of the climate system, paleo-climate archives, theoretical studies of climate processes and simulations using climate models etc. - which provide us with deeper insights about our climate system.

When there was much discussion on the connection of increasing CO2 levels in the atmosphere with climate, to test these hypotheses, Charles Keeling started to measure carbon dioxide (CO2) in the atmosphere in  Mauna Loa in Hawaii, in the late 1950’s. He found that there is a seasonal variation but the undisputed fact was that the levels are shooting up.

Another path breaking development was reconstructing the CO2 concentration in the atmosphere over the last hundreds of thousands of years. An ice core, miles deep, was drilled in Antarctica to reconstruct how the ancient atmosphere looked like. Major fluctuations were noticed as during the Ice Age. But finally, around 11,000 years ago, it became stable leading to the Neolithic Revolution when homosapiens settled down, giving up their nomadic life. Agriculture was invented, and this was the basis for the second big revolution, the Industrial Revolution. Factories were created and this in turn led to a huge spike in CO2 levels over the last 200 years.

From such extended studies it was inferred that human interference is, with a probability of more than 95%, the dominant cause of the recent rapid change in the behaviour of the atmosphere.

Increase in the levels of CO2 and other gases like Methane and Nitrous Oxide create what is known as the Greenhouse Effect. Heat from the sun warms up land and gets radiated back. But the presence of greenhouse gases traps the heat within the atmosphere and causes global warming.

A few of the major consequences of global warming are explained below.

Extreme climate events – We are already witnessing higher frequency of extreme events like increasing heat waves, heavy precipitation causing record flooding, wildfires, cyclones, unprecedented droughts and tsunamis. The resultant loss of lives and damage is huge. When poor developing countries face these extreme events, they are unable to meet the cost of reconstruction and rehabilitation.

Changes in global sea level – Most of the trapped energy, nearly 93%, has gone into warming the oceans. As the ocean warms, it expands; as a result, sea level rises.  There are also contributions from melting glaciers and ice sheets on Greenland, Antarctica and Arctic.

Risks to water resources - Water is tied to food production, energy and industrial production, human and ecosystem health, forestry and infrastructure. Rising sea level brings greater threats to coastal groundwater systems where salt water pushes farther in. This can impact availability of drinking water, leading to tensions and conflicts. There will also be changes in rainfall patterns and rising temperatures that will result in more demand for water by agricultural crops.

Food and agriculture – Heavy rainfall for shorter periods causing floods as well as possible shifts in where that rain falls could greatly impact agriculture and food security across the globe.   Increase in aridity and droughts will cause shortage of water for irrigation and inadequate crops. Negative impacts on the grasslands sustaining livestock systems, destruction of coral reefs leading to reduced fisheries productivity etc. will destabilise food security.

Human health and wellbeing – Climate change could result in food shortages and famines leading to starvation and malnutrition, spread of infectious diseases, increasing menace of pests and other harmful  creatures. It could lead to epidemics like malaria. Vector borne and bacterial diseases, allergies, bronchial problems etc. would show an upward trend.

Loss of biodiversity, migration, political tensions etc. are other predicted impacts of climate change.

The only way to deal with climate change is to reduce emissions through combined concerted action.

Dr. Marianne Fay (World Bank) said, “Climate change cannot be solved without countries cooperating on a global scale to improve energy efficiencies, develop and deploy clean technologies, and expand natural “sinks” to grow green by absorbing gases. If we act now, act together, and act differently, there are real opportunities to shape our climate future for an inclusive and sustainable globalization.”

US and China have agreed to a partnership to deal with the U.N. climate change negotiations that takes place in Paris next year.” (Secretary of State John Kerry said in Jakarta.) The agreement to collaborate between China, the developing world’s largest emitter, and the United States, the developed world’s biggest greenhouse gas producer, could send a powerful signal to other countries to clean up their act.