Duststorms at 114.8 kmph, temperatures touching 47.8 degree C in Delhi and predictions of less than normal rains in north India this year means that the nation has to prioritise environment over development. Climatologists tell SHAlINI SAKSENA that these freak weather conditions witnessed in different parts of the sub-continent have nothing to do with global warming and more to do with rising water temperature over the Pacific Ocean’
May 20, 2014:The Indian Institute of Tropical Meteorology’s first experimental real-time monsoon forecast for this year predicts delayed monsoon advancement over India. Scientists say that the first spell of rainfall will be inadequate and scantier than normal. They opine that a low pressure system over the Arabian Sea is absent, which could slow down the progress of the monsoon. Monsoons generally hit Kerala by June 1, after which it goes northwards up to central India by June 12. This year, the southwestern monsoon reached Kerala by June 6. This means its progress in the rest of the country will get delayed as well.
May 30, 2014: A duststorm, IGI Airport reported a wind speed of 114.8 kmph, and the thunder squall left a trail of death, destruction and chaos in the Capital. Twelve people were killed as trees fell on cars and winds toppled brick piles. More than 350 trees were uprooted.
June 3, 2014: Intense thunderstorms hit Hyderabad and parts of southern Telangana and the Rayalaseema region. It was the same weather phenomenon that was observed in Delhi. Trees were uprooted in areas of the old city and many areas witnessed blackouts as electricity poles fell.
June 8, 2014: Temperature in the Capital touched 45.1° C while it was 47.8° C in and around Palam airport, making it the hottest day in 62 years
This is not the first time that the temperature in the Capital touched 45.1° C in June. Back in 2007, Delhi recorded 48.8°C on June 9. Climatologists say that short winters, scorching summers and erratic rainfall are getting common in India. But it is not just the Capital that is facing this extreme climate. The entire world is facing a major climate change. According to the UN’s World Meteorological Organisation (WMO), which monitors global weather, the first six weeks of 2014 have seen an unusual number of extremes of heat, cold and rain in most parts of the globe.
The WMO assessment reported that Melbourne, Adelaide and Canberra recorded heatwaves in January, while temperatures in Moscow were 11° C above normal. Germany and Spain were 2° C above normal for January and February saw six major depressions develop over the Atlantic. However, the anomaly in weather continued beyond the first two months of 2014. According to the Japan Meteorological Agency’s (JMA) April 2014 report, the deviation in temperature continued in many major cities across the world.
The JMA report shows that all three cities in India — New Delhi, Kolkata and Mumbai — reported an anomaly of minus 1.5° C, 2° C and minus 0.6° C, respectively in their temperature in April 2014. Following the extreme climate change experts UN’s Intergovernmental Panel on Climate Change (IPCC) has exhorted India to control its extreme environment exhaustion. The recently released findings by The Energy and Resources Institute’s 2014 Environmental Survey initiated to gauge the perception, awareness, opinion and behaviour of people towards environment in India, reveal that about 90 per cent know that climate change is a reality, 80 per cent say average temperatures have risen and more than 30 per cent feel that the Government should prioritise environment over development.
However, Dr DS Pai, scientist & head, lRF division, National Climate Centre in Pune, says that it is quite natural to have heatwaves during this period. “In India, the HW conditions are generally experienced during from March to July with a peak during May and June. But it is being increasingly seen that the HW occurrence has been higher in the 2001-2010 decade as compared to earlier four decades. This increase in HW conditions can be associated with global warming to some extent. The change in land use patterns (urbanisation) is another factor,” Pai says.
But he is quick to point out that it is not the HW that is affecting the monsoon. “One has observed that the continuing HW spell is due to the delay in the onset of monsoon over the land. As soon as the monsoon reaches the central parts of the country, some amount of moisture will start entering north India and will reduce the temperatures. In fact, the present heating over the region will help monsoon move further forward. Till that time, HW is likely to continue. One of the reasons for the delay in the onset of monsoon over the country is delayed heating of the Indian sub-continent due to the increasing mid latitude activity (western disturbances) between period January and May which brought clouding over the region,” Pai explains.
Rainfall fluctuations in India have been largely random over a century with no systematic change detectable on either the annual or seasonal scale. The Indian economy is intrinsically linked to the annual monsoon cycle. The annual mean area average surface warming is projected to be between 3.5° C and 5.5° C over the subcontinent by the end of the 21st century. This could be more during the winter than during the monsoon season.
However, the examination and analyses of climate change in South Asia has to be understood against the physical, economical and societal environments of many nations located in this region. The socio-economic environment of several countries in this region is characterised by high population density and relatively low rates of economic growth. Many countries here are quite vulnerable to extreme climate events such as cyclones and floods under current climate.
A rise in temperature — even the relatively small increase of 1° C — would increase rate of evapo-transpiration (Sum of all surface evaporation) by five to 15 per cent. If there were no compensating increase in rainfall, this would tend to reduce yields. In north India, for example, a temperature rise of 0.5° C could reduce wheat yields due to heat stress by about 10 per cent, i.e. if rainfall does not increase. Rice yields under irrigated conditions are significantly affected by temperature and solar radiation. When the minimum temperature increases from 18 to 19° C, there is a decrease in yield of 0.7 tonnes a hectare.
Erratic rainfall is part and parcel of the climate in India. As are cyclones, typhoons, floods and drought. These are trends that one has witnessed in the recent past. But to conclusively say that these can be attributed to climate change, climatologists say, requires more in-depth study. Because there is so much more information available, it has been seen that the cropping cycle has been affected as well. In some States like Bihar, farmers do rely on the weather predictions and plan their cropping cycle accordingly. But a majority of the farmers still depend on the rains and plan their cropping accordingly. This sometimes has disastrous consequences. For example, sowing the seed and no rain. Or rain when the crop has just been harvested.
“As India faces more extreme weather-related events, it is important to study these trends and have an informed debate about it. People are seeking black and white answers about the link between climate change and some of these events. It is important in this context to understand the difference between weather variability and climate change. Every heatwave and drought can’t automatically be due to climate change nor the reverse true. We are seeing more days with higher maximum day temperatures and more erratic rainfall and there is a trend to this but to understand if the root cause of a particular event is climate change and not some other localised factor, we need more modelling at the regional scale to be able to attribute it to climate change,” Uthra Radhakrishnan senior research associate at the Centre for Science and Environment says.
Hence, meteorologists insist that one has to understand the difference between climate change and global warming. While the terms are often used interchangeably, they do have different definitions. Global warming is a more specific term. It refers to increases in the Earth’s average temperature because of greenhouse gas build-up in the atmosphere. Global warming is a cause of climate change which is a a broader term. It refers to changes (increases or decreases) to long-term weather patterns like temperature, rainfall or snowfall. A warmer Earth, from global warming, will lead to changes in rainfall patterns, a rise in sea level and a wide range of impacts on plants, wildlife and humans. When scientists talk about the issue of climate change, their concern is about global warming caused by human activities.
So, in that sense, global warming is something that has to be expected and will continue but it is resulting in unusual phenomenon. “One has to accept that global warming will continue and the oscillations in climate will become even more common. In the last few years the temperatures in certain parts of North India have dipped below minus. And in summers, one sees temperatures touching 48° C. One also sees floods and droughts at the same time. These are all part of climate changes per se, but are not a permanent feature,” climatologist Prof Murari lal says.
Climate is not static and any assumptions made about the future based on the climate of the past may be inappropriate. Assumptions about the probability, frequency and severity of extreme events should be re-evaluated. Climate change issue has presented decision makers with a set of formidable complications: A considerable number of uncertainties the potential for irreversible damages to our ecosystem.
“The kind of weather that we are witnessing is not out of the ordinary. It is just that now, we have the sophisticated tools and satellite to monitor and predict the weather more accurately. The way it has happened this year with El Nino. It’s early onset was predicted as early as February this year. This meant that the country would receive around 93 per cent of annual rainfall. So, far, in the month of June, the deficit has been 50 per cent. But that doesn’t mean that less than normal rain will become a common feature in the country. In fact, come July and August one may see 100 per cent rainfall. This is because El Nino has already started to balance itself out. In other words, its effect is reducing. But because of it, the mid-latitude build up was stronger and we saw a much cooler April and May. It was only in May end and June that the heat wave finally hit the country. This has delayed the monsoon thrust which is slowly building up now,” Prof lal tells you.
He also says that the reason why there is so talk about an impending drought is because it affects the economy of the country. “The yield gets affected and the financial burden on the farmer increases. However, the truth is that India produces enough to feed its 1.3 billion population. The only problem is that we don’t have proper storage facilities. This means that each year we loose tons of foodgrains. Since droughts are a regular feature, it is time that we took measures to ensure appropriate storing,” Prof lal says.
Therefore, there is need to carefully monitor the migrating nature of the monsoon trough and because breaking monsoon (seasonal winds that bring moist air from oceans and seas over land) is a normal occurrence.