Drought is both an environmental pressure, and a consequence of human pressures on the environment.
‘Meteorological drought’ refers to duration without precipitation, relative to local climate, and contributes significantly water shortage.
However, human pressures on the landscape – urban development and agricultural practices making the soil surface impermeable or drainage of naturally wet land – can intensify the effects of drought for the environment and people.
As a global-scale feedback, human-induced climate change can contribute significantly to atmospheric conditions generating drought, with adverse and often severe impacts. For example, Keeley et al. (2015) conclude that “…a drought of the severity and duration of the recent Syrian drought, which is implicated in the current conflict, has become more than twice as likely as a consequence of human interference in the climate system”.
There is a tight interdependence between human activities – as beneficiaries but also as driving forces – and the natural environment with respect to drought.
Humanity and the natural environment
‘Nature’, in its broadest sense, is the core resource of many of the things that support our health, economic activities and broader ‘quality of life’ including future resilience. However, this stark reality remains is far from fully reflected in contemporary lifestyles, regulations and markets.
In fact, a great deal of common understanding about ‘the environment’ leaves its trace our language, for example:
- ‘Environmental impact’ posits the environment solely as a receptor of our impacts, not a fundamental resource supporting our needs;
- ‘Environmental protection’ is then often perceived as a constraint by developers, as in the common cry “A few newts disrupted an important new building project!”, rather than safeguarding of vital resourcs;
- The term ‘flood defence’ embodies a view that floodplains are ours to use and need ‘defending’ from the natural processes that formed them; and
- ‘Improved meadow’ suggest that eliminating grassland biodiversity is an improvement on nature.
This all highlights a conceptual disconnection between ‘the environment’ and human wellbeing, as if they were not fully interdependent and likely to suffer if that connection is broken.
What are ecosystem services?
The need to recognise and internalise human interdependence with nature lies behind the 30+ year genesis of what are now termed ‘ecosystem services’, defined by the UN Millennium Ecosystem Assessment (2005) as “…the benefits people obtain from ecosystems”. In fact, the Millennium Assessment brought the concept of ecosystem services into global policy and public awareness, classifying them into four qualitatively different categories
- Provisioning – things we extract and use;
- Regulatory – moderation of air quality, climate, pest and disease, etc.;
- Cultural – enrichment of human lives spiritually, recreationally, aesthetically, etc.; and
- Supporting – processes maintaining ecosystem resilience, functioning and capacity to produce more directly consumed services.
Other ecosystem service classifications exist (e.g. CICES, UK NEA, etc.), though all seek to articulate the diverse ways in which humanity benefits from natural systems in ways that are vitally important yet often formerly overlooked. Still today, few ecosystem services have associated market values, so remain excluded from mainstream policy and corporate decision-making. Contemporary sustainable development challenges often arise from overlooking important services and our interactions with them.
Drought, environment and ecosystem services
Drought affects the environment, but so too human modification of the environment – atmospheric processes, catchment hydrology, etc. – alters the capacity of ecosystems to supply beneficial ecosystem services, including some that buffer the effects of drought. But drought may modify ecosystem services in negative or beneficial ways, for example:
- Provisioning services: suppressing crop and stock productivity, but favouring dry-adapted medicinal plants;
- Regulatory services: increasing dust generation negatively affecting air quality, but potentially reducing disease transmission by aquatic vectors;
- Cultural services: compromising recreational fisheries and visitor attractions such as wildlife reserves, but land forms of historic interest are often more visible in drier landscapes and drawn-down reservoirs; and
- Supporting services: constraining soil formation and cycling of nutrients, but potentially enhance populations of some dry-adapted wildlife.
Humanity is not merely a beneficiary but is totally dependent upon the range of ecosystem services provided by natural systems. Taking account of the full range of ecosystem services throughout societal activities can help us collectively reduce pressures causing drought, avert at least some of its negative effects, and adapt to a changing climate.
by Dr Mark Everard – Associate Professor of Ecosystem Services at the University of the West of England (UWE Bristol)
Kelley, C.P., Mohtadi, S., Cane, M.A., Seager, R. and Kushnir, Y. (2015). Climate change in the Fertile Crescent and implications of the recent Syrian drought. PNAS, 112(11), pp. 3241–3246. (www.pnas.org/cgi/doi/10.1073/pnas.1421533112, accessed 17th November 2015.)
UN Millennium Ecosystem Assessment. (2005). Ecosystems and Human Well-being: Synthesis. (http://www.millenniumassessment.org/documents/document.356.aspx.pdf, accessed 12th November 2015.)