world’s largest emitters, including the United States, China, India, and
Indonesia.
In Durban, South Africa, in 2011, a UN-sponsored conference achieved a
notable success. All countries agreed to negotiate a legally binding
emission-reduction agreement by 2015, to be implemented by 2020.
Many observers hailed this as a major breakthrough because for the first
time all countries would be taking part in emissions reductions, even
though the details were yet to be determined. The next major step in the
UN process was the agreement achieved in Paris in December of 2015.
The negotiation involved 196 countries; within two years, 174 of those
had formally signed the Agreement. The Paris Agreement aims to achieve
reductions in GHG emissions sufficient to keep the global temperature 2
degrees Celsius (or less) above pre-industrial levels. Each country agrees
to determine and report its own target for emissions reductions, though
there is no mechanism to force any individual country to carry out its
commitment. Canada’s stated target is to reduce its GHG emissions by 30
percent below 2005 levels by 2030.
There is no doubt that getting agreement on emissions reductions from a
large number of countries is a complex and difficult task. But even apart
from the politics and the diplomacy, there are enormous technological
challenges involved in reducing greenhouse-gas emissions. We now turn
to examine these challenges.