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Although we are on the eve of the beginning of autumn in our country, we continue to face high temperatures, for example those forecast for this week in some cities in the central zone. The appearance of new diseases, the miniaturization of some species, the disappearance of the largest individuals in ecosystems and the migration of animals from their habitats are some of the consequences of extreme heat. The academic from the Faculty of Biological Sciences, Pablo Marquet, explains how the increase of 1.1°C registered in the current temperature of the Earth influences these processes.
In March 2022, the World Meteorological Organization (WMO) He warned that “there is a 93% chance that at least one of the years in the period 2022-2026 will become the warmest on record and unseat 2016 from the top spot.”
“As long as greenhouse gas emissions do not cease, temperatures will continue to rise. In parallel, the oceans will continue to warm and become more acidic, sea ice and glaciers will continue to melt, sea levels will continue to rise, and weather conditions will continue to become more extreme”, published a release issued by this agency dependent on the United Nations (UN).
Currently, the planet’s global temperature has increased by 1.1°C, but it is predicted that “there is a 50% chance that global warming will exceed 1.5°C in the next five years,” says the same document. .
He academic from the Department of Ecology of the Faculty of Biological Sciences, Pablo Marquet, explains that this increase in temperature generates transformations in the patterns of air circulation that have flowed at the end of the day. “The entire atmosphere is somewhat disrupted, which makes these phenomena that are called high temperatures, extreme hot events more and more recurring over time; of a lot of rain or very little; or great droughts”.
The expert, who is also a researcher at the Institute of Ecology and Diversity, commented that all living phenomena are supported by chemical reactions. “To be alive is to have a metabolism with which one generates, modifies, transforms chemical compounds and obtains energy from them. Now all these processes respond to basic laws of aerodynamics and there are theories, such as that of Eyring, Evans and Polanyi, that show how temperature affects the rates at which these processes occur”, he says.
“When we increase temperatures, we will affect the speed with which certain types of phenomena occur, which can range from the spread or infection by a virus, to the chemical process associated with the generation of CO2 or its capture”add.
heat impact
“Species move to escape these higher temperatures or eventually lower precipitation conditions. And here is also the problem, because to move you have to have a habitat through which you can do it, but since we have disturbed and transformed the surface of the planet so much, it is often impossible for species, because they have to go through areas that are completely transformed”, explains the ecologist Pablo Marquet. (Photo credit: iStock)
“We are now measuring the impact of temperature on mutation rates and genomic evolution rates with marine and terrestrial databases, to see and expand the theory down to the most molecular level. It is a reality that would allow us understand how temperature could affect processes that are related to evolutionary phenomena”, explains the researcher.
Pablo Marquet comments that with the heat it is the larger organisms that suffer the most, because they are the least capable of dissipating, they get very hot and eventually they can die. “High temperatures are a selective agent, because they can eliminate the largest individuals from populations and contribute to miniaturization, that is, organisms become smaller and smaller, which is a trend that has been seen in different groups. of vertebrates as part of climate change”add.
On the other hand, he warns that there are other species that, due to their conditions, require much more temperate zones. One of the most threatened on the planet are amphibiansfor whom extreme heat creates a double problem as they are highly dependent on water and because they require low temperatures to live.
“Species move to escape these higher temperatures or eventually lower precipitation conditions. And here is also the problem, because to move you have to have a habitat through which you can do it, but since we have disturbed and transformed the surface of the planet so much, it is often impossible for species, because they have to go through areas that are completely transformed”, he highlights.
The academic comments that he also there are species that migrate and can cause a negative impact on health. “An example is the mosquitoes that bring yellow fever or malaria. This has been seen on the Atlantic coast, northern Argentina and the United States. Insects that are highly dependent on temperature and precipitation conditions move quickly, adapting to climate change and with it also carry their diseases.”
«In Patagonia, on the other hand, if the rainfall drops a lot, there are few currents in the rivers and there may be more mixes from the ocean that carry nutrients from the bottom up. If there is a lot of heat and radiation, conditions can be given for the existence of these blooms of harmful algae that can generate losses of billions in salmon companies, affecting the native fauna of fish and whales”, he adds.
Historic pact for biodiversity
In the UN Conference on Biological Diversity, COP15which was held in Canada in mid-December 2022 and in which 188 nations participated, a historic pact in favor of biodiversitywith 23 commitments made by 2030, one of the main ones being to protect and restore at least 30% of the planet’s land and water.
«We have 10 years, but that implies that we should have started yesterday. Everything that is central Chile is very altered, with more than 70% of the ecosystems that have been modified. Many habitats have been lost and there are many species at risk of extinction, there are less than 3% that are protected. The same with the marine and coastal ecosystems, in the north and center of the country where there is much more to protect, the macroalgae forests are an example”, adds the expert.
Pablo Marquet highlights that these 23 agreements are a step forward. “We hope that the climate community, the IPCC (Intergovernmental Panel for Climate Change) and the countries reach an agreement at the next COP that allows them to start walking on two legs: biodiversity and climate change, in order to start fixing things. , because otherwise, we will not be able to “, he concluded.
