The Prince of Wales' three-day climate change meeting for Nobel Laureates begins.
More than 60 scientific experts and 20 Nobel Laureates including US Energy Secretary and physicist Professor Steven Chu will be among those gathering at the event.
The world leaders on global warming will work together to examine the significance of recent climate change science.
Clarence House said the St James' Palace Nobel Laureates Symposium in London would look at "the urgency of action this indicates and the importance of the rainforests as part of a global deal on climate change".
Charles will give a welcome reception and dinner for the delegates.
He will give a speech at a session entitled "Facing the Climate Crisis".
On Thursday, the Nobel Laureates will sign a Memorandum reflecting the Symposium's findings.
Prince Charles has warned that tackling global warming should have a higher priority on the world's agenda than fighting poverty and that there are just eight years left to save the planet.
"We only have 100 months to act," he said in a speech in Brazil this year.
In an unprecedented move for a royal, he launched a web campaign this month calling for urgent action.