We see far greater risk of massive irreversible sea level rise (SLR) at 2°C, on a scale of 12–20 meters or more in the long term. The climate record of the Earth over the pat few million years is quite clear:
Sea Level Rise from Ice Sheets
We see far greater risk of massive irreversible sea level rise (SLR) at 2°C, on a scale of 12–20 meters or more in the long term. The climate record of the Earth over the pat few million years is quite clear:
Sea Level Rise from Ice Sheets
1.5°C Pathways: The IPCC Special Report on 1.5°C of Warming (SR1.5)
In order to remain within 1.5°C, the SR1.5 found that transformative action will be needed in all of the broad major sectors of our global, national and local economies: energy, transport, industry and agriculture. The IPCC found these changes however to be geo-physically, environmentally, technologically and economically within our reach: even advantageous, because many of these changes would bring strong health and development co-benefits.
The only things missing are social and political will: that is up to us.
Source: IPCC Special Report on 1.5° of
Warming, 2018 (Fig. FAQ4.1) and Joeri Rogelj, Grantham/Imperial College London
All of these pathways require rapidly dropping emissions, with a cut by around 50% by 2030; mostly focused on the energy and transport sectors, because the technologies there are already well developed and can be implemented immediately.
Changes in some industries and agriculture may take longer, so these provide more of a focus for the additional 2030-2050 reductions down to carbon neutrality.
After 2050, carbon removal technologies dominate, both to begin to bring temperatures down and to offset small remaining human emissions from activities for which we currently have no carbon-free alternatives.
If we overshoot 1.5°C, that means carbon dioxide removal (CDR) will need to be even greater; but we do not currently have a feasible and reliable means to do this. The only existing means is to reduce emissions, because that we know how to so.
The only things missing are social and political will: that is up to us.
Global CO2 characteristics Pathways limiting warming to 1.5°C with no or limited overshoot (less than 0.1°C):
a) Robust declining trend in next decade
b) Reach net-zero CO2 around mid-century
c) Varying levels of carbon-dioxide removal (CDR)
Non-CO2 emissions are also strongly reduced but do not reach zero globally
Source: IPCC Special Report on 1.5° of Warming, 2018 (Fig. SPM.3A) and Joeri Rogelj, Grantham/Imperial College London
Far greater detail on 1.5-consistent pathways,
challenges and benefits is in
the IPCC Special Report on 1.5°C of Warming.
Subsequent pages give more information on how current 50x30 countries have designed their individual 50x30-consistent pathways; as well as what other countries need to do to get there.