The Prince was looking ahead to a series of critical UN meetings that are due to take place between now and the end of 2020
The next 18 months are going to be crucial to deal with the global heating crisis.
Observers now think that the decisive and political steps will have to happen before the end of next year to cut emissions of carbon dioxide by 45 percent, in a bid to keep the rise in global temperatures below 1.5C.
But last year the Intergovernmental Panel on Climate Change (IPCC) set the 2030 deadline for the cuts in carbon.
The sense that the end of next year is the last chance saloon for climate change which is becoming clearer all the time.
“I am firmly of the view that the next 18 months will decide our ability to keep climate change to survivable levels and to restore nature to the equilibrium we need for our survival,” said Prince Charles, speaking at a reception for Commonwealth foreign ministers recently.
The Prince was looking ahead to a series of critical UN meetings that are due to take place between now and the end of 2020.
Ever since a global climate agreement was signed in Paris in December 2015, negotiators have been consumed with arguing about the rulebook for the pact.
But under the terms of the deal, countries have also promised to improve their carbon-cutting plans by the end of 2020.
Current plans are nowhere near strong enough to keep temperatures below the so-called safe limit.
Right now, we are heading towards 3C of heating by 2100 not 1.5.
As countries usually scope out their plans over five and 10 year timeframes, if the 45 percent carbon cut target by 2030 is to be met then the plans really need to be on the table by the end of 2020.
What are the steps?
The first major hurdle will be the special climate summit called by UN Secretary General Antonio Guterres, which will be held in New York on 23 September.
Guterres has been clear that he only wants countries to come to the UN if they can make significant offers to improve their national carbon cutting plans.
This will be followed by COP25 in Santiago, Chile, where the most important achievement will likely be keeping the process moving forward.
But the really big moment will most likely be in the UK at COP26, which takes place at the end of 2020.
Reasons to be cheerful?
There has been a marked change in public interest in stories about climate change and a hunger for solutions that people can put in place in their own lives.
People are demanding significant action, and politicians in many countries have woken up to these changes.
Ideas like the green new deal in the US, which might have seemed unfeasible a few years ago have gained real traction.
Some countries like the UK have gone even further and legislated for net zero emissions by 2050, the long-term goal that will keep temperatures down.
Reasons to be fearful?
With exquisite timing, the likely UK COP in 2020 could also be the moment the US finally pulls out of the Paris agreement.
But if Donald Trump doesn’t prevail in the presidential election that position could change, with a democrat victor likely to reverse the decision.
Either step could have huge consequences for the climate fight.
Right now a number of countries seem keen to slow down progress.
Last December the US, Saudi Arabia, Kuwait and Russia blocked the IPCC special report on 1.5C from UN talks.
Just a few weeks ago in Bonn, further objections from Saudi Arabia meant it was again dropped from the UN negotiations, much to annoyance of small island states and developing nations.
Earlier this year a major study on the losses being felt across the natural world as result of broader human impacts caused a huge stir among governments.
The IPBES report showed that up to one million species could be lost in coming decades.
To address this, governments will meet in China next year to try to agree a deal that will protect creatures of all types.
The Convention on Biological Diversity is the UN body tasked with putting together a plan to protect nature up to 2030.
Next year's meeting could be a "Paris agreement" moment for the natural world.
If agreement is found it's likely there will be an emphasis on sustainable farming and fishing. It will urge greater protection for species and a limit on deforestation.
Next year, the UN Convention on the Laws of the Sea will also meet to negotiate a new global oceans treaty.