Pakistan reaches 120 ° F as climatic trends cause spring heat

This spring has brought extreme heat to India and Pakistan. Unusually great heat has followed one another since March and continues well in May. The situation is a mystery for rapid research into the role of climate change in this event, as we cannot yet set a date for its end. However, a couple of studies looked at the impact of climate on the March and April heat.

Daily and monthly temperature records have been broken in many areas. The temperature of the thermometers reached 49 ° C (120 ° F), and the heat was accompanied by abnormally dry weather. Record heats often coincide with drought, as dry land heats up even more without the cooling effect of evaporation. However, lower humidity has reduced the heat threat to human health, although at least 90 deaths have been reported so far, and that number is expected to rise.

Working outdoors was extremely difficult, and the effects of the slowdown intensified as the heat increased. The impact on agriculture has been significant, wheat crop losses are already losses estimated at 10-35 percent in northern India, for example. As Ukrainian exports declined due to the war, India had previously planned to increase its own exports, but instead imposed an export ban this month.

It is also hot in Pakistan caused a flood from a glacial lake, destroying a large bridge and a number of buildings, including power plants.

The World attribution of weather The team applied its usual pre-heat analysis by the end of April to tell us about how this is related to climate change. These quick reports are possible because the team uses the same (peer-reviewed) method every time. The goal is not to give a verdict on whether this weather was “caused” by climate change – this is not the right question. Instead, these studies focus on whether we can expect more or less such a picture of the weather in a warming climate. If the answer is “more”, we may ask how much climate change is burdening the bones.

The average daily temperature of Celsius in March and April (left) and their comparison with the average for 1979-2022 (right).  The analyzed area is highlighted in green.
Increase / The average daily temperature of Celsius in March and April (left) and their comparison with the average for 1979-2022 (right). The analyzed area is highlighted in green.


The study has been limited to coverage of daily temperature data since 1979 for the area, starting in 1951 in India – less than ideal for highlighting trends. But to assess the impact of climate change, researchers took from their usual large collection of climate models, including simulations with and without greenhouse gas emissions (and aerosols that reflect sunlight) caused by humans.

The analysis revolves around statistics of rarity of events. According to historical data, this March-April heat is estimated with an annual probability of 1 percent, which is usually called the “100th anniversary event”. But in a 1.2 ° C simulation model of a colder pre-industrial climate, this extreme heat will be an approximately 3,000-year-old event. In other words, climate change has made this heat wave about 30 times more likely.

This can be repeated to simulate a model of future warming. When the world warms up to 2.0 ° C, this heat becomes another 8 times more likely, which means we should expect to see something like this almost every decade.

The UK Meteorological Office has released Fr. a similar analysis last week, though subtle differences in his approach make the final answers a little different. It included a smaller collection of models and used as a benchmark the previous record heat of April-May 2010.

The analysis estimates heat waves in 2010 as roughly a 300-year event in a pre-industrial climate, but only a three-year event between 2013 and 2032. This means that climate change has made breaking the 2010 record about 100 times more likely.

These results are not surprising, given that heat is one of the clearest trends in climate change in extreme weather. But depending on when this heat chain finally subsides, this event could look even more remarkable in the end.

The World Weather Attribution document emphasizes the need for life-saving devices in the region. In addition to the limited availability of air-conditioned premises (deteriorating due to power outages), about half of the population works outdoors. A number of cities in India and Pakistan have “heat action plans” that include activities such as planting trees, cool roofs, event notifications, cooling water centers and providing hospitals with resources to care for people. Such efforts will only become more important as heat waves continue to increase in frequency and intensity.

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