Scientists at the UK Centre for Ecology & Hydrology (UKCEH) are embarking on two new research projects that will transform our understanding of impacts of the climate and biodiversity crises. 

One of the projects will investigate the multiple environmental threats to freshwater biodiversity, while the other will predict which areas will be most affected by humid heat extremes. The £1 million three-year projects are both being funded by UK Research and Innovation (UKRI).

Humid heat is the combination of air temperature and moisture, sources of which include seas, rivers and other water courses, irrigated fields and floodwater. In some parts of the world, humidity is so severe that it reduces the ability of sweating to cool the body down, posing a significant threat to human health.

The impact on people will increase under climate change, particularly in regions such as equatorial Africa and the Indian subcontinent, which are highly populated and already very hot and humid. There is very limited understanding of the meteorological and land surface factors behind humid heat extremes, and an urgent need for people in affected regions to adapt to climate change.

Researchers at the University of Leeds and UKCEH will quantify the relative importance of different drivers of humidity - surface moisture, topography and land cover including identifying the landscape features such as ocean coastlines, lakes, irrigation, wetlands and urban areas that create localised heat or humidity. 

Scientists will map the specific towns that have an increased risk of experiencing the highest maximums in humid heat during widespread extremes that affect a larger region, under both current and possible future climates. 

The results will provide knowledge to improve the prediction of humid heat events, informing the development of early warning systems and urban planning decisions. Some places within the worst-affected regions could become inhospitable.

UKCEH meteorologist Professor Chris Taylor said: “We urgently need to understand the conditions under which humid heat extremes occur because as the world warms, many more people will be exposed to severe risks to their health.”

A project led by Heriot-Watt University and also involving UKCEH, as well as researchers across Europe, will identify the multiple factors driving negative health effects in UK frogs. Scientists will develop a biomonitoring approach to assess the health of wetland ecosystems using this organism.

Temporary freshwater habitats such as marshes and ponds are exceptionally biodiverse and highly exposed to varied environmental threats including pollutants, heatwaves, salinity and invasive species. But they are generally overlooked by researchers and regulators, and few field studies have addressed the effects of different combinations of pollutants and climate stressors on these ecosystems.

This project will fill important knowledge gaps, focusing on frogs because amphibians are a key component of these temporary freshwater ecosystems and also the most threatened class of vertebrates.

The researchers will study the impact of multiple stressors on physiological responses of tadpole populations. They will then develop an online tool that can be used to assess the health of freshwater wetlands, which will help inform conservation efforts. 

Dr Claus Svendsen, Head of Pollution at UKCEH, who is involved in the new project, explained: “Biodiversity is declining at an alarming rate especially for amphibians, and many different factors are driving declines in species in freshwater ecosystems. Our work will enable researchers to identify specific threats and the combinations that are driving negative impacts, and will be widely applicable across freshwater ecosystems.”

In total, UKRI is investing £25 million as part of its Pushing the Frontiers programme, to identify solutions to climate change and other environmental science challenges. There is more information on the UKRI website.