Why geomorphology matters in global environmental change

Global environmental change has become a topic of universal interest, but the emphasis has been almost entirely on the role of changing climate. Climate is only one of the drivers of global environmental change. The indirect drivers of global landscape change include demography, socio-economic trends, and cultural and religious factors. The direct drivers are relief, land use and land cover, sea level and hydroclimate and runoff. Positive feed-backs between human activity, sea level, relief and climate are leading in the direction of ’critical tipping points’. The implications of approaching a ’tipping point’ are that gradual environmental change may be overtaken by rapid change or even a reversal of previously ascertained trends. Human safety and well-being will depend on our ability to respond to such changes. Understandings from geomorphology that are central to the global environmental change problematique include the following: effects of deliberate landscape change via land use or land cover change (this may include extractions from, additions to or transformations of elements of the landscape); effects of sea level change on coastal landscapes and effects of climate, transmitted through hydrology, aridity, vegetation and sediment and solute transport. Examples of changing landscapes are illustrated from polar (Svalbard), temperate (Coast Mountains of western Canada and Austrian Alps) and tropical (Ethiopian Highlands) mountain environments.