The world should focus on delivering decarbonisation promises and engage in international technological cooperation, rather than arguing over agreed upon goals, according to Xie Zhenhua, China’s climate change envoy. Xie, the country’s top climate diplomat, told a webinar on Tuesday that it was more important for countries to pool resources to innovate and share technology to reduce the cost of low carbon energy solutions, than to wrangle over whether to upgrade global goals to keep global warming at 1.5 degrees instead of 2 degrees . “Now is the time for action and implementation of our commitments, not the time to argue whether it should be 1.5 or 2 degrees,” he told the panel discussion organised by Our Hong Kong Foundation and the Hong Kong University of Science and Technology. Xie’s comments were made in response to Todd Stern, the former US special envoy for climate change under the Obama administration, who told the webinar that a consensus was forming among international scientists that the world needed to upgrade the goal to 1.5 degrees. He said this was needed because the world had already seen more heatwaves, wildfires and floods of unprecedented severity in recent years with global warming of 1.2 degrees. Stern added that a 2018 Intergovernmental Panel on Climate Change report suggested that the consequences of a two degree warming will be “far worse” than that of 1.5 degrees. The US and China have committed to cooperating with each other and other nations to tackle the climate crisis, including cooperating in multilateral processes such as the Paris Agreement, Xie said. Given countries were at different stages of economic development and had varied energy resources, developed economies should shoulder their fair share of responsibilities given their longer history of industrialisation by achieving net zero emissions earlier than developing countries, and help the later do so as well, he said. “Different countries have different starting points, and their time to achieve near-zero emissions should also be different,” Xie said. “If the world will achieve carbon neutrality by 2050, developed countries should do so by around 2040, achieve negative emissions by 2050, and provide technology and financial support to developing countries.” Under the 2015 Paris Agreement signed by about 200 nations, countries should make voluntary commitments to decarbonise with a goal to hold global warming within two degrees by 2100 from pre-industrial levels, and use their best efforts to keep it at 1.5 degrees. The next major global climate negotiation will take place in Glasgow in November. Acknowledging that China’s current commitment for carbon emissions to peak before 2030 and achieving net zero emission by 2060 were challenging, Stern said more needed to be done . “While China has pledged carbon neutrality by 2060, which is great … it has not announced plans to do enough in the 2020s,” he said. “Peaking [emissions] in China by 2030 cannot get the job done, and I don’t think it represents the best efforts to hold to 1.5. It can get the job done against two degrees perhaps. “Nor is China’s substantial expansion of its coal [power plants] fleet in the 14th five-year plan (2021-25) compatible with what needs to happen,” Stern said. Lord Adair Turner, the chairman of the UK’s energy transition commission, said the world will have a 50 per cent chance of reaching the 1.5 degree goal and 90 per cent likelihood of attaining the two degree target, if all developed nations become carbon neutral by 2050 and all developing nations by 2060. “If China does not peak emissions until 2030, I do not think we have anything like a 50-50 chance of limiting global warming to 1.5 degrees, nor a 90 per cent chance of keeping [it] below two degrees, because China is so big and so economically successful that what it does is far more important than my own little country does,” he said. Given that the cost of solar and wind power generation and battery storage has fallen 60 to 90 per cent in the past decade, much of it thanks to efforts in China, he said it was possible to build electricity systems primarily based on renewable energy, and generate power more cheaply than using fossil fuels. Even so, Xie said China needed to keep coal-fired plants on reserve in case of power failures in situations such as extreme floods in Henan province , which cut off supply from many of its wind and solar power facilities.