Abstract
We assess climate impacts of global warming using ongoing observations and paleoclimate data. We use Earth's measured energy imbalance, paleoclimate data, and simple representations of the global carbon cycle and temperature to define emission reductions needed to stabilize climate and avoid potentially disastrous impacts on today's young people, future generations, and nature. A cumulative industrial-era limit of ∼500 GtC fossil fuel emissions and 100 GtC storage in the biosphere and soil would keep climate close to the Holocene range to which humanity and other species are adapted. Cumulative emissions of ∼1000 GtC, sometimes associated with 2°C global warming, would spur "slow" feedbacks and eventual warming of 3-4°C with disastrous consequences. Rapid emissions reduction is required to restore Earth's energy balance and avoid ocean heat uptake that would practically guarantee irreversible effects. Continuation of high fossil fuel emissions, given current knowledge of the consequences, would be an act of extraordinary witting intergenerational injustice. Responsible policymaking requires a rising price on carbon emissions that would preclude emissions from most remaining coal and unconventional fossil fuels and phase down emissions from conventional fossil fuels.
DOI
10.1371/journal.pone.0081648
Publication Date
2013-12-03
Publication Title
PLoS ONE
Volume
8
Issue
12
Publisher
Public Library of Science (PLoS)
ISSN
1932-6203
Embargo Period
2024-11-22
First Page
e81648
Last Page
e81648
Recommended Citation
Hansen, J., Kharecha, P., Sato, M., Masson-Delmotte, V., & et al. (2013) 'Assessing “Dangerous Climate Change”: Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature', PLoS ONE, 8(12), pp. e81648-e81648. Public Library of Science (PLoS): Available at: https://doi.org/10.1371/journal.pone.0081648
