Climate change is impacting on the planet in different ways, and there have been some recent severe weather events – as 2019’s Hurricane Dorian shows. Trends also indicated that extreme weather events are becoming more frequent.
Extreme weather
Extreme weather is a difficult concept to define. It includes flooding, wildfires, heatwaves, droughts, cold spells, tornadoes and hurricanes.
In general, ‘extreme weather’ refers to unexpected, unusual, unpredictable, severe or unseasonal weather, when compared with historical data. This can also be geographical, weather which is atypical to one area, but which is typical to another area. Over time, extreme weather events, if they continue, become the norm – the consequence of climate change.
Recent extreme weather events are largely attributed to human-induced global warming.
One example of extreme weather is with “blocking patterns”. Under these circumstances hot or wet weather remains stuck over a region for several weeks. The effect of this is to cause heatwaves or floods. The frequency of such events is increasing have more than doubled in summers over the last decade.
Based on a 2018 study into changing weather conditions, Professor Michael Norton, who is the European Academies’ Science Advisory Council environment program director, said that the “latest data supports our original conclusions: there has been and continues to be a significant increase in the frequency of extreme weather events, making climate proofing all the more urgent. Adaptation and mitigation must remain the cornerstones of tackling climate change.”
New research
The new study hails from Washington University in St. Louis, and it gives new insights into how different species may fare under conditions of extreme weather – what is becoming the new normal.
The model was produced by Professor Carlos Botero. It is significant in that it overturns the concept that species exposed to more variable conditions, in the past, are more likely to survive extreme events.
The model discovered that species which breed a single time in their lifetime have a tendency to evolve relatively conservative behaviors. This is seen by the researchers as if the collective species was expecting to experience environmental extreme regularly.
However, those species where a single individual can reproduce multiple times and in different contexts (the example afforded is with a bird that nests several times in a season and in different trees), then here evolution favors behaving as if environmental extremes simply never happen.
This means the former (more conservative category) can adapt to changes more easily compared with the species that are capable of reproducing multiple times.
According to Botero, with the model “we can have a pretty good idea of how any given species may respond to current changes in this aspect of climate — if we pay attention to its natural history, and have some idea of the climatic regime it has experienced in the past.”
Species adaptation
In some cases, certain species can adapt. The question is with how long such adaptations can continue for before species decline sets in. An example cited by the researchers is with Anolis iguanian lizards, which are found in the Caribbean.
These lizards tend to evolve larger toepads and shorter limb lengths in response to hurricanes because these traits help them cling better to branches during strong winds. However, the model suggests that should such hurricanes increase in intensity and frequency, then this will lead to longer-term population. declines
Research paper
The research has been published in the journal Ecology and Evolution. The research paper is titled “Alternative responses to rare selection events are differentially vulnerable to changes in the frequency, scope, and intensity of environmental extremes.”
Essential Science
This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week we examined new research that shows how the humble aspirin could help to reduce the adverse impact of air pollution upon the lungs. The effects were assessed against different forms of air pollution, across a 28-day period.
The week before we looked at autism. The syndrome is difficult to detect at the early stages and this tends to be based on assessing behavioral signs. To address this issue, scientists are working on a new blood test based on biological markers.
