Drastic phase down of our carbon dioxide (CO2) emissions from burning fossil fuels
within decades will likely be insufficient to avoid seeding catastrophic human‐caused
climate change. We have to also start removing CO2 from the atmosphere, safely,
affordably and within decades. Technological approaches for large‐scale carbon removal
and storage hold great promise but are far from the gigaton‐scale required.
Enhanced chemical weathering of crushed silicate rocks and afforestation are proposed
CO2 removal approaches mimicking events during the Devonian rise of forests
that triggered massive CO2 drawdown and the great late Palaeozoic cooling.
Evidence from Earth's history suggests that if undertaken at scale, these strategies
may represent key elements of a climate restoration plan but will still be far from
sufficient. Climate protests by the world's youth are justified. They recognize the
urgency of the situation and the intergenerational injustice of our time: current and
future generations footing the immense economic and ecological bill for damaging
carbon emissions they had no part in and which world leaders are failing to limit.