Community climate simulations to assess avoided impacts in 1.5 and 2  °C futures
The Paris Agreement of December 2015 stated a goal to pursue efforts to keep global temperatures below 1.5 °C above preindustrial levels and well below 2 °C. The IPCC was charged with assessing climate impacts at these temperature levels, but fully coupled equilibrium climate simulations do not...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-09-01
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| Series: | Earth System Dynamics |
| Online Access: | https://www.earth-syst-dynam.net/8/827/2017/esd-8-827-2017.pdf |
| Summary: | The Paris Agreement of December 2015 stated a goal to pursue efforts to keep
global temperatures below 1.5 °C above preindustrial levels and
well below 2 °C. The IPCC was charged with assessing climate impacts
at these temperature levels, but fully coupled equilibrium climate
simulations do not currently exist to inform such assessments. In this study,
we produce a set of scenarios using a simple model designed to achieve long-term 1.5 and 2 °C temperatures in a stable climate. These scenarios
are then used to produce century-scale ensemble simulations using the
Community Earth System Model, providing impact-relevant long-term climate
data for stabilization pathways at 1.5 and 2 °C levels and an
overshoot 1.5 °C case, which are realized (for the 21st century) in
the coupled model and are freely available to the community. Here we describe
the design of the simulations and a brief overview of their impact-relevant
climate response. Exceedance of historical record temperature occurs with
60 % greater frequency in the 2 °C climate than in
a 1.5 °C climate aggregated globally, and with twice the frequency
in equatorial and arid regions. Extreme precipitation intensity is
statistically significantly higher in a 2.0 °C climate than
a 1.5 °C climate in some specific regions (but not all). The model
exhibits large differences in the Arctic, which is ice-free with a frequency
of 1 in 3 years in the 2.0 °C scenario, and 1 in
40 years in the 1.5 °C scenario. Significance of impact
differences with respect to multi-model variability is not assessed. |
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| ISSN: | 2190-4979 2190-4987 |