Extreme temperatures, wildfires, drought, and flooding have all been made worse by the last eight years, being the hottest on record, according to the World Meteorological Organization.

The U.N. secretary general, Antonio Guterres has insisted the summit had to produce ambitious, credible climate actions.

Our climate editor, Justin Rowlatt, has the latest.

Cyclones ripped through Madagascar earlier this year.

Floods displaced more than a million people in Nigeria last month, while another year of low rainfall pushed parts of Somalia and elsewhere in East Africa, even closer to famine.

Our planet is sending a distress signal.

The U.N. conference in Egypt was warned,

"The last eight years have been the warmest on record, making every each wave more intense and life-threatening, especially for vulnerable populations."

"Sea levels are rising at twice the speed of the 90s, posing an existential threat for low lying island states and threatening billions of people in coastal regions."

Rishi Sunak arrived this evening.

The British Prime Minister will urge the world to move further and faster on the switch to renewable power.

He joins representatives of more than 200 nations.

It is essential; progress is made.

They were told today, "Whilst I do understand that leaders around the world have faced competing priorities this year, we must be clear as challenging as our current moment is, inaction is myopic and can only defer climate catastrophe."

But expect heated negotiations, Egypt says the rich world needs to come good on its promises of cash to help developing countries cut carbon and adapt to our changing climate.

And there'll be demands for money to help vulnerable nations with the climate-related impacts they are already experiencing, like the terrible floods in Pakistan that left a third of the country underwater earlier this year.

The fear is the talks could be deadlocked.

The Ukraine war has driven up food and energy prices worldwide.

Developed nations are expected to say they don't have cash to spare.

Many times, we've been given commitments and promises, but we haven't been given action.

And, of course, a promise that is broken. It kind of destroys the trust that, you know, we have in our leaders.

You don't have to go far from the coast in Egypt to find vivid evidence of what is at stake.

The Red Sea is home to some of the most magnificent and biodiverse coral reefs in the world, but coral is incredibly vulnerable to climate change.

Scientists warned virtually all the world's reefs are likely to be lost by the end of this century, probably sooner.

There really is only one issue on the table here, in Egypt, Reeta, and that is cash.

Rishi Sunak is expected to tell the 120 or so world leaders that will be gathering here tomorrow not to backslide on their promises of finance and support made at Glasgow last year.

But developing countries are looking for more than $100 billion every year.

You got rich, causing the climate crisis by burning fossil fuels.

They've always said to developed nations, "You need to help pay to solve it."

Now, conversations about money are never easy, as we all know.

So we are expecting some difficult discussions here, in Egypt, over the next few days.

Justin, thank you. Justin Rowlatt reporting.