Ripples of climate change: Why India should worry about heatwave conditions

The heatwave conditions in India will be “serious” before monsoon hits various parts of the country, said the World Meteorological Organisation (WMO), as global temperature records were smashed yet again in April.

A small town in Rajasthan called Phalodi recorded a searing 51 degrees Celsius in the afternoon of 19 May establishing the highest temperatures ever recorded in the country. The previous record was held by a place about 200 km away called Pachpadra with 50.6 degrees Celsius in the year 1886.

Though heatwaves are common in India from April through June, this year has seen an exceptionally powerful one. The climate pattern sits well with the general global experience this year of record high temperatures in most parts of the world. Last year, El Niño — a climactic occurrence over the Pacific Ocean that unusually spikes up the ocean temperatures — was blamed for severe droughts and dry spells over southern Africa, South and South East Asia, the US and the western Pacific. The event also boosted powerful west Pacific typhoons.

 Ripples of climate change: Why India should worry about heatwave conditions

Though heatwaves are common in India from April through June, this year has seen an exceptionally powerful one. Representational image. Reuters

The month-long weather system of 2015—one of the most powerful in history—had prompted a food crisis in many parts of Africa. It has substantially inflamed water-related problems across the South East Asian region.

However, the El Nino alone did not cause the heatwaves in India this season because the weather system is rapidly fading and is expected to become neutral this summer itself.

“We don’t have any specific linkage between the El Nino and the specific temperatures in this season,” said Rupa Kumar Kolli, chief of the World Climate Applications Division and Climate Prediction and Adaptation Branch at WMO.

"In terms of the (India’s heat) records (this year), it could be due to a combination of seasonal climatology, the prevailing circulation (wind, cloudiness) in the region as well as long-term trends associated with global warming. When the heat wave season coincides with anomalous circulation factors on specific days, it can help the extremes to develop and persist. The India Meteorological Department closely monitors these situations and has recently set up an excellent heatwave warning system," Kolli said.

The WMO’s South Asia Climate Outlook Forum (SASCOF) – launched in 2010 to engage South Asian countries in understanding and forecasting the monsoon – met in Colombo last month and has predicted above-normal rainfall over much of South Asia.

El Nino that has a significant impact on the Asian monsoon has a high probability of becoming a La Nina weather system — the opposite of El Niño — towards the end of the year. La Niña brings cooler temperatures, abundant rainfall, including to the South East Asian  region, sometimes even flooding countries.

Frequent deficit monsoons are becoming common in India as well as in other parts of the subcontinent. An increase in extreme rainfall events has occurred at the expense of weaker rainfall events over the central Indian region and in many other areas, according to the Intergovernmental Panel on Climate Change (IPCC) findings.

Rapid climate change and thinning snow covers may also have had an impact on the increasing Indian temperatures, like for most other parts of the world.

“Reduced global snow cover, particularly in the northern hemisphere, is partly due to the global increase in surface temperature, including that over India.  Indeed, it has a positive feedback cycle, in the sense that reduced snow cover leads to more absorption of solar radiation by the earth's surface, causing higher temperatures and reducing the snow cover and the cycle continues,” Kolli said.

Hotter days and nights as well as heatwaves have become increasingly frequent in the past 50 years. These will increase this century, according to the IPCC.

The threats on health from rising temperatures are real. Last month, the WMO and WHO hosted a climate and health forum to promote heat-health early warning systems to encourage countries to respond better.

Smashed global records

The WMO called the reports on climate this week as “very alarming”, with April setting new records for high temperatures both on land and on ocean. This is the twelfth consecutive month that saw temperature records being broken – the longest such streak in the last 137 years since the US’ National Oceanic and Atmospheric Administration (NOAA) started keeping records.

Overall, 13 out of 15 highest monthly temperature departures on record have all occurred since February 2015.

NOAA said the combined average temperature over global land and ocean surfaces for April 2016 was 1.10 degree Celsius above the 20th century average of 13.7 degree Celsius. This is the highest temperature departure for April since global records began in 1880.

The globally averaged sea surface temperature was 0.80 degree Celsius (1.44 degree Fahrenheit) above the 20th century monthly average — again, the highest on record.

“What’s particularly concerning is the margin at which these records are being broken. They are not being broken, they are being smashed and on a fairly consistent basis,” said Clare Nullis, spokesperson of the WMO.

The findings of NOAA have been confirmed by NASA and the Japan Meteorological Administration who use different data sets, measurement methods and measurement stations.

There has been extraordinary warmth over large tracts of the Alaska and Russia with temperatures at least 3.0 degree Celsius  above average, as well as in South America, Africa and Asia.

The heat that was seen in 2015 was alarming and hit the world headlines, but the high temperatures in 2016 makes 2015 “pale in comparison”, the world climate organisation said.

In addition, there are two other very concerning events related to high global temperatures. For the first time ever, the carbon dioxide concentrations in the southern hemisphere have joined those in the northern hemisphere and passed the 400 parts per million level. WMO called this "symbolic milestone but significant” since unlike the northern hemisphere where atmospheric concentrations vary, the southern hemisphere remains fairly stable. This implies that the CO₂ levels are not going to go down anytime soon and may remain at that level for several generations.

“At the current rate of increase in CO₂ levels, we are on track to reach the 2 degree Celsius temperature limit within the next two generations,” the WMO chief Petteri Tallas said.

NOAA also reported the thinnest snow cover extent in the northern hemisphere. “This is significant obviously in terms of drought, impact on wild fires (etc.),” Nullis said.

The Canadian wildfires that have grabbed international headlines are partly due to the low snow cover and very little moisture in the air.

Another impact of the prevailing high temperatures has been the unprecedented coral bleaching especially in the Great Barrier Reef.

The combined effect of a now-fading El Niño along with climate change and devastating amounts of human emission have been responsible for the debilitating climate that has affected the world. According to NOAA 10 the Annual Greenhouse Gas Index, human activity has increased the direct warming from effect of CO₂ in the atmosphere by 50 percent above pre-industrial levels during in the past 25 years.

Governments have huddled together in Bonn this week on how to implement the Paris climate agreement.

“El Niño is fading fast and will probably give way later this year to La Niña. But any cooling effect from La Niña will be temporary and will not be enough to rein in the global warming from greenhouse gases," said Taalas.

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Updated Date: May 21, 2016 13:34:39 IST