Showing posts with label Climate Extremes. Show all posts
Showing posts with label Climate Extremes. Show all posts

Feb 15, 2024

New study points to more climate extremes

A new study has found similarities between long-term climatic changes in South Australia and temperate agricultural areas in Argentina -- highlighting similarities across these Southern Hemisphere countries.

As temperature records tumble, and the threat of bushfires and dry conditions looms large, an international study by Flinders University and Argentinian researchers renews the urgency of calls to make more concerted efforts to prepare for climate extremes in South Australia.

Highs and lows in temperature and rainfall indices over the past 50 years have shown an increase in maximum and minimum temperatures of 1.1°C and 0.7°C and less precipitation while pointing to more intense and extended drought periods, extreme summer heatwaves alongside occasional extremes such as frost and flood.

South Australia -- often cited as the driest state on the driest continent -- is poised to see more weather extremes in temperature and precipitation with more storm events, longer and more severe droughts and higher temperature peaks up to 3-5°C above current averages likely to follow global trends, the study shows.

"We found remarkable warming signal trends in both hot and cold extreme weather events," says Universidad Nacional del Sur researcher Dr Federico Ferrelli in a new article supported by Argentina's National Scientific and Technical Research Council.

"This reminds us that we need to focus on climate change mitigation and adapt sustainable management plans to better buffer ecosystems and human health and wellbeing, particularly in areas most exposed to these extreme weather patterns."

Flinders University co-author Professor Patrick Hesp, an expert in coastal dune systems, says that if SA's rainfall continue to decline according to such forecasts, "we can expect to see increased soil erosion in dryland agricultural regions and greater mobility of coastal dune systems -- especially on western coast areas where mean annual rainfall is already quite low."

The researchers used 24 climate extreme indices based on Bureau of Meteorology data to find a significant increase in extreme hot events -- including summer days and tropical night temperatures -- as well as daily maximum and daily minimum temperatures.

While cold indices such as frost days show negative trends, heavy and extreme storms have become more severe locally while rain decreases regionally.

Land management practices, including less land clearance, native plant revegetation and more sustainable agricultural practices, is one step in the right direction.

While Argentina and Australia are economically different countries, the researchers emphasise that the imminent impacts of climate change are reflected in both temperate climate zones in the Southern Hemisphere and impacting on a global scale.

For instance, the Pampas Region in Argentina has experienced substantial increases in maximum, minimum and mean temperatures (1.8 °C, 1.2 °C, and 1.2 °C respectively), with some areas affected by falling precipitation and rising aridity.

"Therefore it is imperative to develop sustainable land management policies to address these issues," researchers say.

"Global warming effects ecosystems, biodiversity, agriculture and food security, water resources, and human health and wellbeing.

"It also contributes to economic and social inequities as vulnerable populations and developing countries are often the hardest hit by the effects of climate change."

Including SA's rising 1.8 million population, extreme temperatures could severely impact cardiovascular and respiratory diseases, vector-borne diseases and affect mortality rates, the researchers warn.

Read more at Science Daily

Aug 31, 2023

Climate extremes hit stressed economies even harder

Economies already under stress respond more strongly to weather events like heat waves, river floods and tropical cyclones, a new study shows. A global economic crisis as during the Covid-19 pandemic strongly amplifies the price increases private households experience from the impacts of weather extremes, a team of researchers from the Potsdam Institute for Climate Impact Research (PIK) finds. The price impacts tripled in China, doubled in the United States and increased by a third in the European Union.

"The unprecedented societal interruptions during the Covid-19 pandemic of 2020 and onward took their toll on economic activity. Lockdowns disrupted supply chains and caused economic losses with implications for private households," lead author Robin Middelanis from PIK explains. "Global stress like this reduces the economic capacity to cope with additional shocks from weather extremes that put even more pressure on already stressed societies." For an individual climate disaster, impacts from local production losses can be flexibly reduced to a certain extent by the support of unaffected production sites in the economic network. Compensation mechanisms like this become more difficult when the world economy is stressed as a whole. The costs for households increase as products run short and become more expensive.

For their study published in the journal Environmental Research Letters, the researchers analyzed two scenarios, framed as a "stressed" economy and a counterfactual "unstressed" economy with full economic capacity. Under both scenarios, they simulated indirect economic impacts from direct local economic shocks caused by climate extremes like heat stress, river floods and tropical cyclones. For this, the interaction of more than 7,000 individual producing sectors and regional consumers connected through over 1.8 million trade links was computed on a daily time scale for the years 2020-2021. The study focuses on the resulting indirect price effects on private households for the three largest economies, the United States, China and the European Union.

Read more at Science Daily