In our lab at the UAEU College of Science Biology Department there is extensive engagement of undergraduate students in research on the impacts of climate change in hot regions. Over the last two years, sixteen undergraduate students have been involved in our research program, including seven students who are actively engaged in the lab at the moment. We are interested in whether species in hot regions may actually be more vulnerable to rising temperatures than has widely been thought.
Temperatures in the hottest regions on Earth are rising by less than those in the cooler northern regions, and until now, less than 1% of all the world’s research into climate impact has been focused on the Tropics. The impact of a small temperature increase in a region which is already too hot could however be much more negative than a large temperature increase in a region which is too cold. The vulnerability of species in hot regions thus depends on whether they are living in conditions which are already too hot (i.e. whether they are already living above their optimal temperatures), and it is not immediately clear whether this is actually the case.
While temperatures are much hotter here than in the cooler north, warm-blooded species like mammals and birds actually choose to regulate their bodies at quite high temperatures, ranging from 36’C to 43’C, which suggests that metabolic processes actually run best at high temperatures - warmer than those found even in many parts of the Tropics.
Our projects have therefore been designed to find out whether organisms from hot regions are already living above their optimal temperatures and whether climatic warming could then have negative impacts upon them.
We have studied fish from various tropical regions around the world (Africa, Asia, and South America), observing their breathing rates to quantify metabolic performance at different temperatures and then comparing the temperatures in their natural environments with these temperatures which optimize metabolic performance.
We have found that optimal temperatures differ quite a lot between species, ranging from just above 20’C to just above 35’C. For three of our species, we found they are still living below their optimal temperatures, so warming of their tropical habitats could actually have positive effects. However, for the rest, we found they have already reached or exceeded their optimal temperatures, and the impacts of climatic warming will indeed be negative.
If the majority of species in hot regions are already living above their optimal temperatures, then even just small climatic changes could have a much more negative impact than the larger temperature increases we are seeing in the cooler northern latitudes.
Most of the world’s universities are located in cooler temperate regions, but the students of the UAEU are working hard to redress the balance and shine some light on the impacts of climate change in these hotter regions of the world.