Reduced-complexity model for the impact of anthropogenic CO<sub>2</sub> emissions on future glacial cycles
<p>We propose a reduced-complexity process-based model for the long-term evolution of the global ice volume, atmospheric CO<span class="inline-formula"><sub>2</sub></span> concentration, and global mean temperature. The model's only external forcings are...
Guardado en:
| Autores principales: | , |
|---|---|
| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
Copernicus Publications
2021
|
| Materias: | |
| Acceso en línea: | https://doaj.org/article/4001f09c820144598aaa5330888a4b3c |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| Sumario: | <p>We propose a reduced-complexity process-based model for
the long-term evolution of the global ice volume, atmospheric CO<span class="inline-formula"><sub>2</sub></span>
concentration, and global mean temperature. The model's only external forcings
are the orbital forcing and anthropogenic CO<span class="inline-formula"><sub>2</sub></span> cumulative emissions. The
model consists of a system of three coupled non-linear differential
equations representing physical mechanisms relevant for the evolution of
the climate–ice sheet–carbon cycle system on timescales longer than
thousands of years. Model parameters are calibrated using paleoclimate
reconstructions and the results of two Earth system models of intermediate
complexity. For a range of parameters values, the model is successful in
reproducing the glacial–interglacial cycles of the last 800 kyr, with the
best correlation between modelled and global paleo-ice volume of 0.86. Using
different model realisations, we produce an assessment of possible
trajectories for the next 1 million years under natural and several
fossil-fuel CO<span class="inline-formula"><sub>2</sub></span> release scenarios. In the natural scenario, the model
assigns high probability of occurrence of long interglacials in the periods
between the present and 120 kyr after present and between 400 and 500 kyr
after present. The next glacial inception is most likely to occur
<span class="inline-formula">∼50</span> kyr after present with full glacial conditions developing
<span class="inline-formula">∼90</span> kyr after present. The model shows that even already
achieved cumulative CO<span class="inline-formula"><sub>2</sub></span> anthropogenic emissions (500 Pg C) are capable
of affecting the climate evolution for up to half a million years, indicating
that the beginning of the next glaciation is highly unlikely in the next 120 kyr. High cumulative anthropogenic CO<span class="inline-formula"><sub>2</sub></span> emissions (3000 Pg C or higher),
which could potentially be achieved in the next 2 to 3 centuries if
humanity does not curb the usage of fossil fuels, will most likely provoke
Northern Hemisphere landmass ice-free conditions throughout the next half
a million years, postponing the natural occurrence of the next glacial
inception to 600 kyr after present or later.</p> |
|---|