Protesters took to the streets Friday in London’s historic financial district to lobby against the use of fossil fuels ahead of the start of the U.N. climate summit in the Scottish city of Glasgow.

The protests in London, which were joined by Swedish climate activist Greta Thunberg as well as many other young campaigners from around the world, are part of a global day of action before leaders head to Glasgow for the U.N. Climate Change Conference, known as COP26. Many environmentalists are calling the Oct. 31-Nov. 12 gathering the world’s last best chance to turn the tide in the battle against climate change.

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The protesters included Friday for Future activists from Africa, Asia and the Pacific, who called out the banks for financing activities such as deforestation, mining and polluting industries, which they blame for the destruction of their homes and their futures.

“As much as we are passionate to be here, we shouldn’t have to be here,” said Brianna Fruean from Samoa. “Our pain, our suffering, our tears and our sorrows shouldn’t be what it takes to take action. We already know what we need to do: we need to phase out of the fossil fuel era, we need to divest from these industries that are causing this harm and despair.”

The mood music ahead of the climate talks appears fairly downbeat, with British Prime Minister Boris Johnson, the summit’s host, saying it’s “touch and go” whether there will be a positive outcome.

On Friday, U.N. Secretary General Antonio Guterres warned at the Group of 20 summit of leading industrial and developing nations that “there is a serious risk that Glasgow will not deliver.” He said that despite updated climate targets by many countries, the world is “still careening towards climate catastrophe.”

The protest in London began at the Climate Justice Memorial outside the insurance marketplace of Lloyd’s of London, where red flowers spelling out “Rise Remember Resist” were laid.

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The focus later centered on the headquarters of international bank Standard Chartered, where the few dozen protesters, including Thunberg, chanted “Keep it, Keep it, Keep it in the ground!” and “Ensure our future, not pollution!” A vigil outside the Bank of England will round out the day’s protests.

“We have companies like Standard Chartered who are funding our death,” said Collette Levy-Brown, a climate activist from Botswana. “People are slowly dying. In Africa, we are seeing the climate crisis already.”

Across the world, demonstrators have been taking to the streets to urge action now, including in coal-reliant Poland, where city sirens sounded at noon in Warsaw and other major cities. Poland’s conservative government has been slow to embrace new climate goals, arguing that the country needs more time to phase out its heavy dependence on coal.

The summit in Glasgow is taking place a year late because of the coronavirus pandemic. Six years ago in Paris, nearly 200 countries agreed to individual plans to fight global warming. Under the Paris pact, nations must revisit their previous pledges to curb carbon pollution every five years and then announce plans to cut even more and do it faster.

The headline goal set in Paris was to limit global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) since preindustrial times, yet the world has already warmed 1.1 degrees Celsius (2 degrees Fahrenheit) since then.

The hope is that world leaders will cajole each other in Glasgow into doing more, while ensuring that poorer nations struggling to tackle climate change get the financial support they need to adapt.

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The U.N.’s Guterres said, however, there are “serious questions” about some of those emissions pledges and noted that collectively they won’t be enough to keep the global temperature rise below 2 degrees Celsius.