At the rate that humans are stuffing carbon into the atmosphere, the planet may suffer irreversible damage that could be felt tens of thousands of years, a new study has warned.
Discussions on climate should go beyond what happened in the past 150 years and their impact on the world’s warming and the resulting sea level rise by this century’s end – and instead consider the longer-term effects, urged the authors.
Paleoclimatologist and study lead author Peter Clark warned that the effects of climate change on Earth will be felt for thousands of generations.
"Much of the carbon we are putting in the air from burning fossil fuels will stay there for thousands of years - and some of it will be there for more than 100,000 years," said Clark of Oregon State University in an official statement.
Thomas Stocker, climate modeler and co-author of the analysis, said this focus shift should reflect on the policy level as well. "It is high time that this essential irreversibility is placed into the focus of policy-makers,” he said.
The team analyzed the effects of four levels of carbon emissions, from 1,280 to 5,120 billion metric tons, released into the atmosphere from year 2000 to 2300.
While carbon pollution fell to zero by 2300 in each of the four levels, the impact of the ensuing damage remained for another 10 millennia. In the high-end scenario, global temperatures peak at 7 degrees Celsius in 2300 yet drop by only 1 degree over the next 10,000 years.
In the high-end scenario, rise in sea levels is pegged at 50 meters, although occurring over a number of centuries to millennia. Even low-end scenario saw a rise by up to 25 meters, which directly affects 10 percent of the population of 122 countries, Clark estimated.
“We can’t keep building seawalls that are 25 meters high,” Clark said, warning that entire city populations will eventually need to move.
Thus, slight to significant carbon emissions reduction may no longer be enough to spare future generations from the rage of climate change. Considering the long-term scales of the carbon cycle and of climate change, leaders should target zero or even negative carbon emissions immediately, Clark recommended.
"Taking the first steps is important, but it is essential to see these as the start of a path toward total decarbonization," said co-author and Harvard geology professor Daniel Schrag.
The findings were published in the journal Nature Climate Change.
In a separate analysis, Martin Rees of the University of Cambridge highlighted three “politically realistic” measures for mitigating climate change. “[P]oliticians won't gain much resonance by advocating for a bare-bones approach that entails unwelcome lifestyle changes -- especially if the benefits are far away and decades into the future,” he said.
First, all countries could enhance energy efficiency through steps such as better building insulation, which could even save money.
Second, cuts to methane, black carbon, as well as chlorofluorocarbon emissions could be targeted – all secondary contributors to warming yet already wreaking havoc on local cities such as in China.
Third, countries should conduct more research and development into all low-carbon energy forms such as renewable, fusion, and more.
Photo: Andrea Della Adriano | Flickr