Researchers from TCD have questioned the logic of citing ‘tipping points’ in climate policies as this concept could have dangerous consequences.
The concept of climate ‘tipping points’ – which suggest ecosystems can absorb a given amount of pressure before hitting a dangerous threshold – are frequently cited in environmental and climate science.
However, researchers from Trinity College Dublin (TCD) and Germany have claimed that despite best intentions, tipping points are an unhelpful concept and potentially dangerous in terms of the development of environmental policies. For example, a policy may exist on the basis that if warming is kept below a certain threshold, ecosystems will continue to operate in a safe space.
Their study, published to Nature Ecology and Evolution, used information from meta-analyses – comprised of data from many field experiments – to understand how ecosystems respond to change. In particular, the analyses looked at the consequences of present-day and future pressures, such as increased CO2 or nutrient levels, and assessed the functional responses of ecosystems, such as changes in the cycling of elements or the production of biomass.
‘Abandon the idea of safe operating spaces’
In total, the researchers used information from 36 meta-analyses covering 4,601 unique field experiments on natural or close-to-natural ecological communities. Only three of these meta-analyses showed statistical evidence for a threshold or tipping point where a certain amount of environmental pressure resulted in an extremely strong response.
“I think we need to abandon the idea of safe operating spaces,” said Dr Ian Donohue of TCD’s School of Natural Sciences.
“It gives the completely erroneous impressions that small pressures do not affect ecosystems at all, and that we can continue with business as usual so long as we keep our damage below a certain level. Instead, our research demonstrates that responses to even the smallest pressure can be large.”
He went on to say that if we wait to see clear tipping points emerge in the environment, “we risk overlooking the small gradual changes which sum up to a shifting baseline over time”. The researchers believe that policymakers should work with more nuanced criteria to be able to develop more scientifically accurate actions and goals.