Many world leaders and activists expressed disappointment this weekend with the climate deal that emerged from two weeks of heated negotiations in Glasgow, Scotland – warning that countries will have to strengthen their commitments if they want to avert disastrous consequences and help at-risk nations cope with the damage that’s already occurring from climate change.

“We must end fossil fuel subsidies, phase out coal, put a price on carbon, protect vulnerable communities from the impacts of climate change and make good on $100 billion climate finance commitment to support developing countries,” United Nations Secretary General António Guterres said in a video after the agreement won approval from nearly 200 nations. “We did not achieve these goals at this conference but we have some building blocks for progress.”

Echoing that message, European Commission president Ursula Von der Leyen said in a statement that while some progress was made on the goals of COP26, more work remains and the key to determining the impact of the conference will be how the commitments secured in Glasgow are implemented.

She said, “1.5 degrees Celsius remains within reach; but the work is far from done.”

As part of the pact agreed upon in Glasgow, countries committed to reassessing their targets to cut emissions by the end of next year and to providing more aid to nations bearing the brunt of climate change. But these voluntary measures do not put the world on track to limit Earth’s warming to 2.7 Fahrenheit above preindustrial levels, a central goal of the 2015 Paris accord.

“We’re all well aware that, collectively, our climate ambition and action to date have fallen short on the promises made in Paris,” said Alok Sharma, the British minister of state and president of the Glasgow talks, who appeared emotional Saturday after delegates from China and India proposed a last-minute edit that weakened a provision in the text to phase out fossil fuels.

The paragraph initially called for the “phaseout of unabated coal and inefficient fossil fuel subsidies,” but the final agreement refers only to a “phase-down.”

A key unresolved question is how much more rich nations will to do help vulnerable nations – particularly island nations who face the threat of extinction from rising sea levels – from the damage wrought by climate change.

A video played at COP26 showed the foreign minister of the Pacific island nation of Tuvalu giving a speech while standing knee-deep in seawater.

“The difference between 1.5 and 2 degrees is a death sentence for us,” the environment minister of the Maldives Aminath Shauna said Saturday.

The United States, which took on a position of leadership at COP26 after four years of near-absence in the global climate conversation under President Donald Trump, celebrated the Glasgow climate pact but called for more action.

“The text sets out a path to increase the commitments and actions of countries starting next year, outlines new rules of the road for the Paris Agreement that will provide transparency for countries to turn words into actions, and doubles the amount of support that is going to vulnerable countries to enhance their resilience to the crisis,” a statement from the White House read. “But it is not enough.”

“More work remains as we leave Glasgow to get where science tells us we need to be and the United States will continue to push for more progress at home and abroad in this decisive decade for climate action,” the statement continued.

Boris Johnson, the prime minister of the United Kingdom, struck a more upbeat tone in his statement following the conclusion of COP26.

“We asked nations to come together for our planet at COP26, and they have answered that call,” Johnson said in a statement. “There is still a huge amount more to do in the coming years. But today’s agreement is a big step forward.”

“I hope that we will look back on COP26 in Glasgow as the beginning of the end of climate change,” he said, “and I will continue to work tirelessly towards that goal.”