What are the effects of climate change? Impact of rising temperatures explained as COP26 gets under way

Even if an increase in average global temperatures is kept below 1.5C, the world could still see dramatic changes

World leaders are facing calls for urgent action to limit dangerous temperature rises as they gather for crunch UN climate conference, COP26.

As he assumed the role of COP26 president, Alok Sharma told the formal opening session of the climate summit in Glasgow that it is the last, best chance to limit global warming to 1.5C.

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Sharma said he believed the conference could launch a decade of ever-increasing ambition and action.

However, he warned countries gathered for the talks, which aim to prevent dangerous temperature rises, that they would succeed or fail as one.

But what would the effects of climate change be? And why should we be so worried?

Here is everything you need to know.

What would happen if the world surpasses 1.5C?

Scientists warn that the most dangerous impacts of climate change, including rising seas and extreme weather, will be felt if average global temperatures rise by more than 1.5C.

Beyond this, it is thought that the planet will suffer devastating impacts , including droughts, heatwaves, hurricanes and floods.

At the formal opening of the COP26 climate summit in Glasgow, Patricia Espinosa, UN climate chief, told delegates that the world stood at a “pivotal point in history”.

“Humanity faces stark but clear choices. We either choose to achieve rapid and large-scale reductions of limiting emissions to keep the goal of limiting global warming to 1.5C or we accept that humanity faces a bleak future on this planet.”

She said people can either choose to boost adaptation efforts to deal with weather disasters and build future resilience, or “accept that more people will die, more families will suffer and more economic harm will follow”.

So is keeping temperatures below 1.5C the answer?

Even if an increase in average global temperatures is kept below 1.5C, the world could still see dramatic changes.

Parts of the world will still disappear under water even if COP26 achieves its climate target, Alok Sharma has warned.

He warned that even if that ambition is achieved, it will not put a stop to rising sea levels caused by global warming swamping some countries.

Sharma told Sky News’ Trevor Phillips On Sunday programme that “1.5C really matters”.

He added: “We know from the IPCC (the Intergovernmental Panel on Climate Change) that we are already at global warming of 1.1C above pre-industrial levels.

“At 1.5C, there will be countries in the world that will be under water and that’s why we need to get an agreement here on how we tackle climate change over the next decade.”

Marshall Islands climate envoy Tina Stege said her country will be gone within the next 50 years if nothing is done about climate change, with even a 1.5C rise “unimaginable” for the nation, which sits just two metres above sea level.

Lord Deben, chairman of the independent Climate Change Committee, said 1.5C “has to be attainable” in Glasgow or it will not just be the Marshall Islands fearing for its future, but parts of Europe as well.

The Tory peer told Sky News: “Places like Bangladesh, which are entirely beneath the sea level, large parts of the United States and of Europe, where great cities will be losing very large sections.”

Why is COP26 important?

COP26 is seen as the moment when countries must deliver on pledges made in the accord agreed in Paris six years ago, to limit temperature rises to well below 2C above pre-industrial levels and pursue efforts to curb warming to 1.5C – beyond which the worst impacts will be felt.

There is also pressure on developed countries to deliver a long-promised 100 billion US dollars a year (£73 billion) in climate finance for poorer countries least responsible for and most vulnerable to climate change, and address loss and damage caused by the impacts of global warming.

And there will be efforts to drive action by countries, regions, and businesses to curb emissions in sectors such as power with efforts to phase out coal, as well as finalise parts of the Paris climate accord agreed in 2015 to make it effective and operational.

Countries’ plans for cutting emissions in the next decade – key to limiting long term temperature rises – leave the world well off track to meet the climate goals and put the planet on course for a dangerous 2.7C of warming.

Glasgow is not expected to close that gap, so there is pressure to negotiate a road map for increasing ambition in the next 10 years to keep the 1.5C goal within reach.

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