China and the U.S. agreed in a joint statement on Saturday to work together to combat climate change. It was issued during a trip by U.S. climate envoy John Kerry to Shanghai.
Referencing the U.S.-China joint statement, Xi said China "looks forward to working with the international community, including the United States, to jointly advance global environmental governance."
"China will promote joint efforts to build a Green Belt and Road to benefit the people of all countries," Xi said.
The Chinese president said developed countries need to make concrete efforts to help developing countries accelerate the transition to green and low-carbon development, while full recognition should be given to developing countries contribution to climate action and accommodate their particular difficulties and concerns.
But as the leaders took turns speaking about their commitments, Swedish environmental activist Greta Thunberg issued a video message saying they were hardly enough.
"These very insufficient targets are better than nothing, but we cannot be satisfied with something just because it's better than nothing," she said.
"The gap between our so-called climate targets and the overall current best available science should no longer be possible to ignore," she warned.
India has proposed to decrease its emissions intensity per gross domestic product by 33% to 35% by 2030 from 2005 levels. The country has faced growing pressure from the international community to curb its emissions, which have surged with its economic growth.
But Indian Prime Minister Narendra Modi told the summit that his country's per capita carbon footprint is 60% lower than the global average. "It is because our lifestyle is still rooted in sustainable traditional practices," he said, and encouraged the world to make the philosophy of "Back to Basics" an important pillar of economic strategy for the post-COVID era.
South Korea President Moon Jae-in reaffirmed the country's commitment to carbon neutrality by 2050, a goal first announced last year. Seoul has also raised its nationally determined contribution for 2030 under the Paris Agreement. South Korea peaked its greenhouse gas emissions in 2018.
Having stopped issuing permits for new coal plants domestically, South Korea will also end public financing for overseas coal fired power plants, Moon said, adding that it will scale up investment in renewable energy home and abroad.
The EU targets a 55% cut from 1990 levels by 2030, while the U.K. enacted legislation Tuesday aiming for a 78% reduction over the same period.
The Biden administration looks to make Washington a global leader on the issue, in a complete turnaround from the approach taken by predecessor Donald Trump. Biden signed an executive order on the first day of his presidency to return the U.S. to the Paris climate accord and announced the upcoming summit shortly thereafter.
Washington's previous goal was to cut greenhouse gas emissions between 26% and 28% compared with 2005 levels by 2025.
Biden and Suga agreed during their meeting Friday to launch a bilateral climate partnership to achieve the goals of the Paris accord and interim 2030 targets as well as develop clean-energy technology and promote decarbonization in the Indo-Pacific region and elsewhere.
Russian President Vladimir Putin also attended the summit. Russia plans to reduce greenhouse gas emissions by 30% by 2030 from 1990, according to its proposal to the U.N. It likely hopes to improve its deteriorating ties with the U.S. through cooperation on climate change.
Countries around the world are scrambling to fight climate change in response to the concentration of greenhouse gases in the atmosphere more than doubling in the past 50 years.
Carbon emissions have skyrocketed worldwide since the 1970s due to the increased use of coal and petroleum, and currently outpace the amount that plants and the ocean can absorb. This means that atmospheric levels of greenhouse gases are only expected to rise.
By country, China is the world's largest total emitter of greenhouse gases, followed by the U.S. and India. But the U.S. tops the list per capita. Cooperation between these countries, as well as the EU and emerging economies, will be crucial to effective international negotiations on emission curbs.
Electricity production and heating are now responsible for over 40% of global emissions. Increasing the share of renewable energy like solar and wind power and reducing the use of carbon-intensive coal will be key to shrinking the sector's carbon footprint.
The transportation sector, which is the next largest greenhouse gas emitter, is also starting to shift from gasoline-fueled vehicles to electric alternatives.
Researchers at the U.N. and other institutions have warned that the world must significantly reduce carbon emissions by 2030 to limit climate change, regardless of whether it can achieve carbon neutrality by 2050. The U.N. and the EU are urging the rest of the international community to set more ambitious goals for 2030 to prevent irreversible damage.