SINGAPORE - The United Nations' top climate science panel released a major report on Monday (April 4), outlining how nations can transform the global economy towards a safer future by cutting fossil fuel emissions that are endangering humanity and the planet.
The report by the Intergovernmental Panel on Climate Change (IPCC) says global greenhouse gas emissions need to peak before 2025 to limit dangerous climate change.
But it also says solutions are at hand, that nations are taking action and some key green technology costs have plunged in recent years.
In short, there is hope, and climate policies can be positive for economic development.
For example, from 2010 to 2019, the unit costs of solar energy plunged 85 per cent, wind energy 55 per cent and lithium-ion batteries 85 per cent, says the report. During this same period, solar deployment expanded 10 times, and it was 100 times for electric vehicles.
"We are at a crossroads. The decisions we make now can secure a liveable future. We have the tools and know-how required to limit warming," said IPCC chairman Hoesung Lee, adding that he was encouraged by climate action being taken in many countries. But much more was needed.
The report by the IPCC's Working Group III (WGIII) focuses on cutting emissions, as well as costs, methods and the impact on sectors and technologies.
It is the IPCC's third and final instalment of a multi-year assessment on the science, impact and solutions to climate change. It is the most contentious of the three reports.
This is because it deals with issues that are among the hardest to tackle when facing manmade-climate change: the need to shift away from fossil fuels, the speed at which it needs to happen and the huge costs in rewiring the global economy by going green, especially for poorer nations.
Emissions from burning coal, oil and gas are pushing up global temperatures. These emissions, chiefly carbon dioxide (CO2) and methane, are fuelling increasingly severe climate change impact and humanitarian crises. Yet fossil fuels remain central to many economies.
"Without immediate and deep emissions reductions across all sectors, limiting global warming to 1.5 deg C is beyond reach," says the IPCC.
Limiting warming to 1.5 deg C above pre-industrial levels is a key goal of the 2015 Paris climate agreement. Beyond this threshold lies a future beset by more severe weather and faster sea-level rise, a world humanity has never experienced.
The world has already warmed 1.1 deg C.
"Climate change is the result of more than a century of unsustainable energy and land use, lifestyles and patterns of consumption and production," said WGIII co-chairman, Professor Jim Skea of Imperial College London. "This report shows how taking action now can move us towards a fairer, more sustainable world."
For instance, cleaner energy generation and electric vehicles can slash air pollution. Greener buildings and a focus on public transport and green spaces can cut energy use and make cities healthier places to live.
Growing food more efficiently can save forests and other ecosystems threatened with clearance. Forests and grasslands also soak up CO2.
Professor Navroz Dubash, a coordinating lead author of the report, noted that there are a lot of policy options at reasonable cost in terms of tonnes of carbon emissions reductions.
He said that for about half of all the emissions reductions needed to limit warming to 1.5 deg C, it would cost less than US$100 (S$136) to reduce a tonne. And about a quarter of the emissions can be reduced at less than US$20 a tonne.
"So that's a very positive message and cuts across various sectors and approaches," Prof Dubash, of the Centre for Policy Research in New Delhi, told The Straits Times.
The IPCC said limiting warming to around 1.5 deg C requires global greenhouse gas emissions to peak before 2025 at the latest, and be reduced by 43 per cent by 2030. Methane, which is more potent at trapping heat in the atmosphere than CO2, would also need to be reduced by about a third.
"It's now or never, if we want to limit global warming to 1.5 deg C," said Prof Skea.
Disputes over references to finance were one of the issues that bogged down the report's formal approval process over the past two weeks.
Poorer nations want more financial help and more leeway to use fossil fuels for a longer time, while rich nations are being urged to make deeper cuts first.
The report was written by 278 scientists and released after negotiations between the authors and government officials from nearly 200 nations.
The meeting was needed to approve line by line a 63-page summary for policymakers. This is a much shorter version of the report and politically much more tricky since once governments have approved it, they cannot row back on the document.
This led to accusations that some of the conclusions were watered down under political pressure.
Report lead author, Professor Frank Jotzo, told ST that it was normal for every aspect of the report to be scrutinised, often in great depth.
"The fact that governments take such a strong interest in the approval process is testimony to the importance of the IPCC's reports. If the reports were not consequential, approval would not be contentious," said Prof Jotzo, who is from the Crawford School of Public Policy at the Australian National University in Canberra.