• chevron_right

      Record monsoon flooding in Pakistan due to a confluence of factors

      news.movim.eu / ArsTechnica · Friday, 16 September, 2022 - 16:20 · 1 minute

    Flooding in Pakistan's Sindh province.

    Enlarge / Flooding in Pakistan's Sindh province. (credit: Ali Hyder Junejo )

    In August, Pakistan set destructive records as it averaged more than triple its normal August monsoon rainfall. In the southern provinces of Sindh and Balochistan, the number was seven to eight times the average. The resulting flooding killed around 1,500 people and displaced more than 30 million—a catastrophe of incredible scale.

    Is this an event we expect a warmer climate to have influenced? As they often do, the World Weather Attribution team quickly analyzed this question and released the results on Thursday. Their peer-reviewed method for these rapid studies is to apply standardized analyses to both historical weather data and climate model simulations. The goal is to find out whether a given weather pattern is part of a long-term trend and then determine whether we expect such a trend to come as a result of human-caused global warming.

    Lots of factors

    This event is more complex than something like a short-lived heatwave, given that it played out in waves over weeks and depends on highly variable monsoon patterns. Monsoon rains result from the seasonal transport of moist air over land combined with uplift that cools that air, wringing the moisture out of it. This pattern is hit-or-miss in Pakistan, as it often originates over eastern India and bends northward before it can reach Pakistan.

    Read 9 remaining paragraphs | Comments

    • chevron_right

      Record-breaking UK heat “extremely unlikely” without climate change

      news.movim.eu / ArsTechnica · Friday, 29 July, 2022 - 15:28 · 1 minute

    A red-orange sky over the Houses of Parliament.

    Enlarge (credit: Peter Zelei Images )

    Early last week, the UK experienced something it is very much not known for—extremely hot and dry weather. The heatwave shattered all-time national records, surpassing a 38.6° C (101.5° F) mark set in 2019 by crossing 40° C (104° F) for the very first time.

    The scientists behind the World Weather Attribution project use a standardized (and peer-reviewed) method to rapidly analyze weather extremes like this in the context of climate change. While there is more nuance to this science than saying an event should or shouldn’t be blamed on climate change, we can say something about the role that climate change plays. And for heatwaves, that role is often quite clear: In a warming world, the statistics of heatwaves will necessarily shift toward hotter temperatures.

    The analysis of this event involves two complementary steps. First, the historical data is used to calculate the rarity of this extreme weather event in today’s climate—and what it would have been before the world warmed by about 1.2° C (2.2° F). Second, large collections of climate model simulations with and without human-caused warming are similarly examined for trends in the type of regional weather pattern that produced the event.

    Read 9 remaining paragraphs | Comments

    • chevron_right

      Pakistan hits 120°F as climate trends drive spring heatwave

      news.movim.eu / ArsTechnica · Monday, 23 May, 2022 - 16:05 · 1 minute

    Image of the Sun in a hazy, orange sky.

    Enlarge (credit: Chuchart Duangdaw )

    Spring has brought remarkably extreme heat to India and Pakistan this year. Unusually extensive heatwaves have followed one after another since March and are continuing well into May . The situation presents a conundrum for rapid studies of the role of climate change in this event, as we can’t yet put an end date on it. Nevertheless, a pair of studies have looked into the influence of the climate on March and April's heat.

    Daily and monthly temperature records have been broken in many areas. Thermometers have hit temperatures as high as 120°F (49°C), and the heat has been accompanied by abnormally dry weather. Record-breaking heatwaves often coincide with drought, as the dry ground heats up even more without the cooling effect of evaporation. However, the lower humidity has reduced the heat's threat to human health, though at least 90 deaths have been reported so far, and that number is expected to rise.

    Working outdoors has been extremely challenging, and the impacts of the slowdown have added up as the heat drags on. The effect on agriculture has been significant, with wheat yield losses already estimated at 10–35 percent in areas of northern India, for example. With Ukrainian exports down because of war, India had previously been planning to increase its own exports but instead instituted an export ban this month.

    Read 9 remaining paragraphs | Comments