1. Home
2. Columnist

Global warming and its impact on climate change has arrived

By Yashwardhan Joshi. Dated: 7/12/2019 10:48:24 AM

For years scientists and experts have been warning of global warming and its impact on climate change. The subject has been heatedly debated on international fora time and again with world leaders agreeing on reducing greenhouse emissions in a decade or so.
But it now seems the scientific predictions had underestimated the severity of the crisis all along. Climate change is not just imminent, it is already there. What we have been debating about has hit us on the face. Mumbai had been parched dry for almost the entire June, but the rainfall the city received in the remaining two days is what it gets in the entire month. The deluge of rain for the past six days has swept Mumbai off its feet, submerging houses, roads and rail tracks.
This phenomenon of short burst of devastating rain after a long spell of dry patch is all a result of global warming. Scientists warn that erratic rainfall as well as extreme weather events, such as droughts, floods and heat waves, are going to occur more frequently in the future.
Delhi witnessed a more than 48 degree Celsius this June, Chennai went tap dry, and reservoirs in several other cities became almost dry as dust.
Official data suggest that India has become much hotter in recent years, with 11 of the 15 warmest years occurring between 2004-2018.
The erratic rainfall is also showing its adverse impact on agriculture, altering cropping pattern and yields as well as afflicting crops with new pests and disease.
In Odisha, early flowering of mango and mahua has been seen with devastating effects. Western Odisha is increasingly experiencing desert-like climate; the day time temperatures are rising and the night-temperatures falling.
In Lalitpur, Uttar Pradesh, where a similar study has been conducted, traditional crops and seeds have disappeared altogether from the villages. Also, rainfall in 20 of the past 28 years was less than the average. It has also been found that crops such as pulses and mustard are maturing early and grains remain undeveloped because of the now absence of dew which was once common in November and December 15-20 years ago.
According to scientist N H Ravindranath, who headed the first study that analysed climate change in India's Himalayan Region , 12 States, including Assam, Mizoram and Jammu and Kashmir, are "highly vulnerable" with little capacity to resist or cope.
Another study -- spanning 40 years of observations by NASA spy satellites across India, China, Nepal and Bhutan -- has clearly indicated that climate change is eating the Himalayan glaciers. The glaciers have been losing the equivalent of more than a vertical foot and half of ice each year since 2000 because of rising temperatures -- double the amount of melting that took place from 1975 to 2000.
The analysis shows that eight billion tonnes of ice are being lost every year and not replaced by snow, with the lower level glaciers shrinking in height by 5 meters annually.
In the long term, this will have serious consequences on those who rely on the great rivers that flow from the peaks into India, Pakistan, China and other nations.The increasingly uncertain and irregular water supplies will adversely impact one billion people living downstream from the Himalaya mountains in south Asia, the study says.
Even the BJP-led NDA government has stated that six Himalayan glaciers monitored by the National Centre for Polar and Ocean Research (NCPOR) have been retreating in the range of 13 to 33 millimetres a year. An Australian report has gone as far as to warn of a threat to human existence because of climate change. It envisages a "hothouse Earth" scenario by 2050, with the West Antarctic Ice Sheet and a sea-ice-free Arctic summer appearing well before 1.5°C of warming, Greenland Ice Sheet well before 2°C, and widespread permafrost loss and large-scale Amazon drought and dieback by 2.5°C.
It further warns of sea levels rising 0.5 metres by 2050, and further increasing 2-3 metres by 2100. As much as 35 per cent of the global land area and 55 per cent of the global population will face more than 20 days a year of lethal heat conditions, beyond the threshold of human survivability, it says.
It has even painted a ghostly picture with some of the world's most populous cities, including Mumbai and Chennai, lying abandoned. Many have dismissed such reports in the past, but not anymore. If we do it now, we will do it at our own peril, for the results of global warming are in front of our very own eyes-- when water comes in cascades after weeks of dry spell in Mumbai, when long-lost corpses of climbers who failed to return started emerging from melting ice and snow along trails on Mount Everest, when the only sources of drinking water run dry.
If we don't wage a war for saving water, we will be condemned to wage a war over water.
—[IFS]