Glasgow hosts the latest global climate change summit, under the UK's presidency.
COP stands for "Conference Of Parties" (the parties being the various jurisdictions of the world), and this the 26th meeting was due to take place last year but was postponed for a year due to the pandemic.
Heads of state, scientists, and negotiators from around the world will converge on Glasgow (or at least will attend virtually if Covid-19 impacts the proceedings) for 12 days to work on a path to net zero carbon emissions by 2050.
COP26 is the first time that the world has met to commit to enhanced ambition since COP21 in 2015, when the Paris Agreement was signed.
As part of the Paris Agreement, every five years countries are required to ratchet up their commitments.
The COP26 web site says:
"We must agree a balanced negotiated package that delivers the Paris Agreement and moves the UN Climate Change process forward.
To ensure success, we need all countries to commit to reaching net zero emissions as soon as possible, and to significant further cuts by 2030.
And we must step up and help societies and economies adapt to climate change – particularly the most vulnerable.
We must finally turn the corner on polluting energy systems and seize the opportunity of rapidly falling costs of renewables and energy storage.
We must accelerate the transition to zero carbon transport, phasing out petrol and diesel engines.
To make all this possible, we must accelerate the green transformation of the financial system so all countries can drive clean and resilient investment.
We must harness the innovation and commitment of all – citizens, investors, business, countries, cities and regions – to move the global economy to net zero."