"Ever since governments at the 2015 Paris climate summit set 1.5°C as the
desired limit for global warming, scientists and journalists alike have
regularly asked whether it is achievable. The question arose again recently
when the UN published a report of national emission-cutting pledges for the
next decade. It will be posed regularly before the publication of the IPCC’s
Sixth Assessment Report in July – a synthesis of the most recent information
scientists can offer on climate change – and the UN climate summit in November.
Science is already clear that the 1.5°C target can be met. But science cannot
say whether it will be met. The outcome depends on two things we cannot know
with precision: how sensitive the climate system is to rising greenhouse gas
concentrations, and how quickly the world will cut emissions.
Humanity has little sway over climate sensitivity. But on the second issue –
what we do about emissions – humanity clearly holds the lever of influence."
*** Xanni ***
Chief Scientist, Xanadu
Partner, Glass Wings
Manager, Serious Cybernetics