tolerance

Too hot for people

November 22, 2023 By EarthWise Leave a Comment

The effort to mitigate the effects of climate change has a goal of keeping the global temperature increase below 1.5 degrees Celsius above preindustrial levels. To date, the average global temperature has increased by more than 1 degree. We hear about rising sea levels, powerful storms, and various other alterations in climate and weather patterns. A new interdisciplinary study by three institutions looked at the impact of surpassing the 1.5-degree level upon people being able to withstand heat and humidity.

Humans can only withstand certain combinations of heat and humidity before their bodies begin to experience heat-related health problems such as heat stroke and heart attacks.

In human history, temperatures and humidity that exceed human limits have been recorded only a limited number of times and only for a few hours at a time, in the Middle East and Southeast Asia.

According to the new study, if global temperatures increase by 2 degrees Celsius above preindustrial levels, the 2.2 billion residents of Pakistan and India’s Indus River Valley, the one billion people living in eastern China, and the 800 million residents of sub-Saharan Africa will annually experience many hours of heat surpassing human tolerance.

If the warming continues further to 3 degrees, heat and humidity levels that surpass human tolerance would affect the Eastern Seaboard and the middle of the US from Florida to New York and from Houston to Chicago.

The worst heat stress will occur in regions that are not wealthy and that are experiencing rapid population growth. But even wealthy nations will not escape from the expansion of conditions that are too hot for people.

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Climate-driven extreme heat may make parts of Earth too hot for humans

Photo, posted June 28, 2018, courtesy of Ivan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

RNA Modification For Plants | Earth Wise

September 8, 2021 By EarthWise Leave a Comment

We have heard a lot about RNA this past year as messenger RNA vaccine technology has been used for the first time to combat the Covid-19 pandemic. Now RNA-based technology has shown promise to make major contributions to agriculture.

A group of researchers at the University of Chicago and two Chinese universities have announced that manipulating RNA can allow plants to yield dramatically more crops as well as have better drought resistance.

Adding gene encoding for a protein called FTO to both rice and potato plants increased their yield by 50% in initial field tests. The plants were larger, produced longer root systems, and could better tolerate drought conditions. Further analysis showed that the plants had increased their rate of photosynthesis.

FTO protein erases chemical marks on RNA. Specifically, it controls a process known as m6A, which is a key modification of RNA. The FTO erases m6A to reduce some of the signals that tell plants to slow down and reduce growth. Plants modified with the addition of FTO produced significantly more RNA than control plants.

Experiments with both rice plants and potato plants – which are completely unrelated – demonstrated the same results, indicating that the technique could be broadly applicable. (The genetic modification is rather simple to make and has worked with every type of plant the researchers have tried it with so far).

These results are just the beginning but demonstrate the potential of a technology that could help address problems of poverty and food insecurity at a global scale as well as responding to climate change. The world depends on plants for everything from wood, food, and medicine, to flowers and oils. This technique has the potential to dramatically increase the stock material we can get from most plants.

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RNA breakthrough creates crops that can grow 50% more potatoes, rice

Photo, posted September 22, 2014, courtesy of Toshiyuki Imai via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Heat-Resistant Corals

August 31, 2018 By EarthWise Leave a Comment

All over the world, coral reefs are being wiped out by rising sea temperatures brought about by climate change. When sea temperatures get too high, the symbiotic relationship between coral polyps and microscopic algae living within the coral breaks down and the coral either digests or expels the algae. The result is coral bleaching which weakens, and if it persists, kills the coral.

Coexisting With Dangerous Carnivores

February 16, 2016 By WAMC WEB

We come across many things that we don’t like but that are nonetheless good for us or good for the world in general. On some level, we all make cost-benefits analyses to decide what to do about various things that we might just as soon do without.