An extreme heatwave in India and Pakistan has left more than a billion people in one of the most densely populated parts of the world facing temperatures well above 40℃. Although it has not broken all-time records in the regions, this is still the hottest time of the year.
The heatwave is not over, but it is already testing people’s ability to surviveThis has led to crop failures Power blackoutsIt could be worse, but that is the scary part. Other at some point India is “due” an even more intense heatwave.
Together with a few other climate scientists, we recently looked for the most extreme heatwaves globally over the past 60 years – based on the greatest difference from expected temperature variability in that area, rather than by maximum heat alone. Our results, which are now published in the journal, do not include Pakistan and India. Science Advances. Despite having high temperatures and heat stress levels in absolute terms, heatwaves in India or Pakistan have not been that severe when measured in terms of deviations from the local norm.
We actually highlighted India as a country with a particularly low historical maximum. In the Data we evaluated, we didn’t find any heatwaves in India or Pakistan outside three standard deviations from the mean, when statistically such an event would be expected once every 30 or so years. In 1998, the most severe heatwave in southeast Asia was five standard deviations above the mean. An equivalent outlier heatwave in India today would mean temperatures of over 50℃ across large swaths of the country – such temperatures have only been seen at localised pointsSo far.
Our research suggests that India could experience more extreme heat. Assuming that the statistical distribution for daily maximum temperatures is generally the same worldwide, a record-breaking heatwave will likely occur in India at some time. The region has not yet had to adapt to such high temperatures, so it may be particularly vulnerable.
Harvests and good health
Even though the heatwave isn’t breaking any all-time records yet, it is still remarkable. Many parts India have experienced theirs. hottest April on record. The heat so early in the year can have devastating effects on crops in a area where many rely on the harvest for their livelihood. Usually, extreme heat in this area is closely followed by cooling monsoons – but these are still months away.
Not just crop harvests will suffer, as heatwaves can also impact infrastructure, ecosystems, human health, and human well-being. Human health is complicated because of both the meteorological (how hot and humid) and socioeconomic (how people live and adapt) factors. Although we know heat stress can cause long-term health problems such as heart disease, kidney failure, and respiratory distress, we won’t be able to predict how many people will die from this heatwave. Lack of required health dataFrom India and Pakistan
What does the future hold?
We must consider both climate change as well as population growth when considering the impact of extreme heat on the Indian subcontinent over the next few years. It is a combination of both that will increase the human-health effects of extreme heat in the Indian subcontinent.
Our new study examined how extremes will increase in the future. We used a large collection of climate model simulations that provided us with a lot more data than was available for the real-world. The statistical distribution of extremes relative to a shift within the underlying climate, as it generally gets warmer, doesn’t change, we found. The climate models show that daily temperature extremes increase at the exact same rate as the shifts in the average climate. The IPCC’s latest reportIt was predicted that heat waves in south Asia will be more intense this century. Our results support this.
The heatwave currently affecting more than 1.5 billion people is expected to continue for 50 years. An additional 30% increase. This will mean that hundreds of millions more people will be born in a region likely to experience more severe and frequent heatwaves. With even larger numbers of people being affected by even greater heat extremes in the future, measures to adapt to climate change must be accelerated – urgently.