• However, scientists warn that there is a 6-10% chance of meeting this threshold, and that even if pledges are fully delivered the temperature rise will be closer to 2C.
• Both Mr Sharma and Ms Sturgeon referenced the Russian invasion, with the Scottish first minister saying it is "forcing countries in Europe to rethink long-held assumptions about energy policy and energy security".
Image: GETTY IMAGES
Global leaders have not done enough to honour commitments made at the COP26 climate summit, its president has said.
Alok Sharma said more must be done to hit the targets agreed in Glasgow, warning that failure would be "an act of monstrous self-harm".
Six months on from the event, he said countries needed to "up the pace" in the push towards carbon-neutral energy.
Scottish First Minister Nicola Sturgeon will also issue a warning over climate change later, during a trip to the US.
She is expected to say that a failure to hit targets agreed at COP26 would be "catastrophic" for the planet.
He said it was understandable that climate change was no longer on the front pages, amid the war in Ukraine and the cost-of-living crisis.
But he said these issues "should increase, not diminish, our determination to deliver on what the world agreed in Glasgow".
The summit was aimed at hammering out agreements that would hold average global temperature rises under 1.5C.
However, scientists warn that there is a 6-10% chance of meeting this threshold, and that even if pledges are fully delivered the temperature rise will be closer to 2C.
Mr Sharma said "the window of time we have left to act is closing fast", with climate change "already wreaking havoc".
He said: "Progress is of course welcome, but frankly we need to up the pace. Leaders have not done enough to deliver on their Glasgow commitments, and that must change.
"We need every nation to pick up the pace. We need every leader to show that their words were not hollow, that their commitments were made with integrity, and that they recognize that though the immediate challenges we face are grave, we will only inflame them if we falter.
"It is leaders who made promises, it is leaders who must honor them."
Mr Sharma told BBC Scotland that in the final moments of the Glasgow talks "I genuinely thought there was a point where we weren't going to get a deal".
He said "we have to be hopeful" that global temperature rises can be held down, while warning that "we need to act now".
Ms Sturgeon will also highlight her fears about the climate emergency when she addresses the Brookings Institute in Washington DC later.
She will say: "Six months on from COP26, the world looks very different, but many of the challenges we faced then remain.
"As things stand, the world is on course to exceed both 1.5C of global warming and the 2C threshold - and scientific consensus is overwhelming that this will be catastrophic.
"We need to move at pace to develop clean energy sources and act in a way which shows solidarity with communities in our countries who might otherwise get left behind, and with the global south."
Image: PA MEDIA
Last week US climate envoy John Kerry said the war in Ukraine had not wrecked the Glasgow Climate Pact agreed in November.
Both Mr Sharma and Ms Sturgeon referenced the Russian invasion, with the Scottish first minister saying it is "forcing countries in Europe to rethink long-held assumptions about energy policy and energy security".
And Mr Sharma highligted the "danger of energy systems powered by foreign fossil fuel", calling instead for a focus on "low cost home grown renewables the price of which cannot be manipulated from afar".
According to a UN report, the world is on track to warm by 3.2C this century if countries only follow through on commitments made before the Glasgow summit.
This would lead to "unprecedented heatwaves, terrifying storms, and widespread water shortages".
To avoid that fate, the world must keep the rise in temperatures at or under 1.5C this century, researchers have said, and reach peak CO2 emissions by 2025.