Reducing the impact of extreme environmental events using Environmental Evidence

Authors: Andrew S. Pullin & Teri M. Knight

Many would argue that a significant and positive outcome was achieved at the recent Paris summit (COP21) on climate change in December. We may have a real political mandate for action but the world is still in for some rough weather over the coming decades and good quality evidence will be needed to inform our actions where and when extreme events occur.

Record breaking extremes of climate are being experienced in terms of high temperature, rainfall and strong winds. These events impact directly on human populations through the increased frequency and severity of heatwaves, drought, floods and storms. They also lead to secondary effects such as fires and coastal inundations. Further, indirect consequences include food and safe water insecurity, the spread of disease vectors, poor sanitation, increased air pollution and displacement of populations. In relation to health, these negative impacts affect both physical and mental well-being.

Whilst humanitarian responses may be well rehearsed for emergency healthcare and engineering, the potential contribution of environmental science as a resource for decision makers during and after environmental extreme events is largely unrealised.

Environmental science has played a primary role in predicting the impacts of climate change and has a fundamental role to play in suggesting interventions to reduce the severity of extreme events through engineering solutions such as flood defences, fire breaks, hurricane-proof buildings, making urban centres cooler in heatwaves etc. However, environmental evidence is not normally looked to in the aftermath of an extreme event. This should change.

In reality, when emergency medical aid has been supplied most communities also require interventions to help them get back to self sufficiency. This points to an important need for reliable and robust evidence in a whole range of environmental areas such as how to decontaminate fresh water supplies, replant crops and desalinise agricultural soils.

Over a longer term the devastating impacts of droughts, flood and fires on human communities is also devastating for the ecosystems on which those populations depend for services such as freshwater, food and raw materials. There is a crucial role for environmental evidence in providing solutions to restoring ecosystems following extreme events. Much of the current research focusses on building resilience in natural systems but intervention will be required in many cases where extreme events have weakened or exceeded that resilience. Some specific examples where intervention is already necessary are salinized soils, bleached coral reefs, fire-affected forests, drought-affected grasslands and inundated flood plains. Of course, a lot of relevant evidence already exists but the practice of systematic review and evidence synthesis is still underdeveloped in the environmental sector. As a global society that is threatened by environmental change, we are desperately underprepared when it comes to having an accessible and reliable environmental evidence base that can inform the decisions that will be needed as climate change really begins to demonstrate its potential to impact on human populations. The Collaboration for Environmental Evidence (CEE) is a global network formed to promote and disseminate systematic reviews in the environmental sector. CEE has 6 centres in 4 continents, provides guidance on the conduct of systematic reviews to CEE standards, publishes systematic reviews and maintains an open access library of these. Although some links have been made to agencies working in international development and humanitarian aid, significant capacity building is required to enable the CEE network to realise the potential for environmental science to reduce the impact of environmental disasters.

To find out more about CEE or to help us build this capacity, visit or contact the authors.

Andrew PullinAndrew Pullin is Chair of Trustees of the Collaboration for Environmental Evidence and Professor of Evidence-Based Conservation at Bangor University, UK





Teri Knight is a Consultant in Public Health working with Public Health Wales, UK and a Trustee of the Collaboration for Environmental Evidence.

Views expressed through our blog are those of the author(s) alone and do not necessarily reflect the official position of Evidence Aid.