Sian Crampsie

A new report from the Intergovernmental Panel on Climate Change (IPCC) has called for increased levels of investment in the global energy system in order to limit global warming to 1.5°C above pre-industrial levels.

The report calls for annual investments of around $2.4 trillion in the global energy system between 2016 and 2035 to limit emissions and enable a green industrial revolution on an ‘unprecedented’ scale.

The report will form a key scientific input into the upcoming Katowice Climate Change Conference in Poland this December, when governments from around the world will meet to discuss progress on the Paris Climate Agreement. It warns that a global temperature increase of more than 1.5°C could have catastrophic and irreversible impacts on natural, managed and human systems.

“This report warns that the dangerous effects of climate change will hit us sooner than most people had thought, unless we take much faster, much deeper action to limit potentially devastating global temperature rises by slashing carbon emissions to net zero by 2050,” said Emma Pinchbeck, executive director of RenewableUK. “This is a great economic opportunity for our country and for consumers. As well as generating more clean electricity using cheap technologies like onshore wind, and fully commercialising our innovative wave and tidal industries, we need to see much greater progress on decarbonising the heat and transport sectors.”

The report notes that limiting global warming to 1.5°C remains a possibility, but will require “rapid and far-reaching” transitions in land, energy, industry, buildings, transport, and cities. Global net human-caused emissions of carbon dioxide (CO2) would need to fall by about 45 % from 2010 levels by 2030, reaching ‘net zero’ around 2050.

This means that any remaining emissions would need to be balanced by removing CO2 from the air, IPCC said. It would also mean that renewables would have to supply 70-85 % of electricity demand by 2050, and coal-fired generation would be close to zero.

“Limiting warming to 1.5°C is possible within the laws of chemistry and physics but doing so would require unprecedented changes,” said Jim Skea, co-chair of IPCC Working Group III.

Allowing the global temperature to temporarily exceed or ‘overshoot’ 1.5°C would mean a greater reliance on techniques that remove CO2 from the air to return global temperature to below 1.5°C by 2100. The effectiveness of such techniques is unproven at large scales and some may carry significant risks for sustainable development, the report notes.

The report is designed to give policymakers the information they need to tackle climate change, and points out that limiting warming to 1.5°C instead of 2°C will have significant benefits and vastly reduce the risks associated with warming, which include wildfires, extreme drought, floods and food shortages.


Key messages

“One of the key messages that comes out very strongly from this report is that we are already seeing the consequences of 1°C of global warming through more extreme weather, rising sea levels and diminishing Arctic sea ice, among other changes,” said Panmao Zhai, co-chair of IPCC Working Group I.

“Every extra bit of warming matters, especially since warming of 1.5°C or higher increases the risk associated with long-lasting or irreversible changes, such as the loss of some ecosystems,” said Hans-Otto Pörtner, co-chair of IPCC Working Group II.

The report was widely welcomed by policymakers and energy industry organisations. “This report aims to create urgency in our response to reducing greenhouse gas emissions,” said Dr. Jennifer Baxter, head of Engineering at the Institute of Mechanical Engineers. “We have technological knowledge to dramatically reduce emissions, we now require the leadership to make tough decisions on regulations for energy efficiency and emissions that may not be politically popular.”

Dr Baxter added: “The IPCC’s target to generate 70-85 % of electricity from renewables is ambitious, but we have to look at the broader picture and focus on reducing the carbon intensity of the whole electricity system. Currently renewables are backed up by gas when they are not generating, and in the UK, gas is backed up by coal.”

One option for decarbonisation is increasing investments in nuclear energy, Dr Baxter said. She added: “Going beyond the electricity system, we should explore the relationship between nuclear and producing hydrogen through electrolysis to provide decarbonised fuel for heat, transport and industry.”

Justin Bowden, national secretary of UK-based workers’ union, the GMB, echoed Dr Baxter’s comments. “GMB is calling on the UK government to step up investment in hydrogen to decarbonise the UK gas network as a top priority.

“Hydrogen is a solution that will benefit the 26 million UK homes using gas for heating and cooking, those working in the gas industry and crucially it can reduce emissions from central heating by 73 %.

“Meanwhile Britain still needs at least five new low carbon nuclear power stations if we are to meet our energy needs and reduce our dependency on foreign imports of power whilst ensuring we have the reliable electricity that comes from very low carbon nuclear, and lower carbon gas, to complement our growing renewable energy sources.”