The writer is chair of the energy transitions commission

Xi jinpings announcement last week that china would achieve carbon neutrality before 2060 was greeted with surprise. few outside china expected this hugely important commitment so soon. but it reflects three motivations: awareness in china that climate change will cause it huge harm; a desire to be a responsible global leader; and growing confidence that technological progress can make net-zero emissions attainable without interrupting chinas path to prosperity.

That confidence is justified by dramatic global changes over the past 10 years. solar electricity costs have fallen by 90 per cent, wind by 60 per cent and lithium-ion battery costs by 87 per cent. initial public subsidies have created such strong economies of scale and steep learning curves that the need for subsidies is diminishing fast. over the next decade, the cost of producing green hydrogen via electrolysis will also fall significantly.

As a result, countries can now build zero-carbon electricity systems with total costs no higher than for fossil fuel-based systems. they should electrify as much of the economy as possible. in passenger road transport, that will be straightforward and cheap. in more challenging sectors, such as steel and cement, aviation and shipping, carbon capture and storage, bioenergy and hydrogen will also play a role.

As the energy transitions commissions making mission possible report shows, all sectors in developed economies could achieve zero emissions by 2050 and all developing countries by 2060. they can do so largely within their own operations rather than relying on offsets bought from elsewhere. the estimated cost, around 0.5 per cent of global gross domestic product in 2050, will be immaterial compared with the potentially catastrophic impact of uncontrolled climate change.because china will by 2050 be a fully developed rich economy, its before 2060 target should at some stage be advanced to 2050. given its technological prowess and commitment to combat climate change, it almost certainly will.

More than 1,100 businesses and 45 of the worlds biggest investors have already set net-zero targets. those commitments will drive tech developments that reduce the cost of achieving them, encouraging others to commit. the chances that the global energy and industrial system will get close to net zero by 2050 are now high.

But the chances of avoiding seriously harmful climate change remain worryingly carbon by mid-century is essential, but not sufficient.from january to june this year, siberian temperatures were 5c above average; massive wild fires have ravaged australia and california; exceptional heatwaves scorched northern india; and china has faced huge floods. by 2050, these effects could get far worse even with a zero carbon economy. accumulated emissions over the next 30 years matter as much as the level in 2050.

The effects so far reflect global warming of just 1.1c above pre-industrial levels. to limit warming to 1.5c, we must not only achieve zero emissions by mid-century, but cut emissions 50 per cent by 2030 after an increase of emissions of 10 per cent in the past decade. achieving that latter cut will be more difficult than zero by 2050. with clear targets and strong policies, we can transform our energy and industrial systems over 30 years. but in the near term, the potential is constrained by capital equipment from internal combustion engines to coking coal blast furnaces already in place.

Action over the next decade is therefore just as crucial as mid-century targets. all growth in electricity systems should now come from zero-carbon sources, and all rich countries should close existing coal plants as fast as possible. road transport electrification should be accelerated by early bans on the purchase of new internal combustion vehicles. and consumers have an important role to play: reducing car and air travel can cut emissions in the years before zero-carbon options are widely available.

But this will not be enough to deliver the 2030 target. so that means there is a major role for nature-based solutions preventing deforestation and sequestering carbon in soils by changing the way we use land. countries and companies should therefore commit not only to reaching net zero by 2050, but to making big reductions by 2030, using purchased offsets to achieve faster progress than internal action can achieve.

Last week was a great one in the fight against climate change. now we need commitments to the challenging objective of big emissions reductions over the next decade.