THE world must reduce greenhouse-gas emissions to “net zero” by 2050 if global warming is to be limited to 1.5ºC, a new report from the world’s leading scientists has said.

The report by the Intergovernmental Panel on Climate Change (IPCC), published on Monday, draws on more than 6000 studies across two years, and has been adopted by the member states of the United Nations.

The IPCC says that to achieve this target would require “rapid, far-reaching, and unprecedented changes in all aspects of society”. It would, however, deliver “clear benefits to people and natural eco-systems”, as well as “ensuring a more sustainable and equitable society”.

Impacts such as this summer’s deadly heatwaves in Europe, Typhoon Mangkhut in the Philippines, and Hurricane Florence in the US, are being felt as the world experiences one degree Celcius of warming. But the scientists say that the world is currently on track for a rise of three degrees.

They predict that anything over two degrees would spell the end of all coral reefs, seriously reduce polar ice, and raise the sea level by an extra ten centimetres. The damage would be significantly less if the increase could be limited to 1.5ºC, reducing the risk to millions of coastal dwellers around the world. The IPCC believes that this is achievable.

But drastic action would be needed, they say. This would involve the rapid decarbonisation of energy use to reduce global greenhouse-gas emissions by 45 per cent by 2030, and to net-zero by 2050.

Those most vulnerable to the effects of global warming of more than 1.5ºC are the world’s poorest people, who have done the least to create this crisis. A coalition of the Least Developed Countries (LDCs) said that the report showed that previous commitments to limit warming to 2ºC would not be enough to protect millions of their citizens.

The chair of the LDC group, Gebru Jember Endalew, from Ethiopia, said: “Communities across the world are already experiencing the devastating impacts of 1°C global warming. Each fraction of a degree that global temperatures rise is extremely dangerous.

“Limiting global temperature increases to 1.5°C means significantly decreased levels of food insecurity, water shortages, destruction of infrastructure, and displacement from sea-level rise and other impacts. To the lives and livelihoods of billions, that half a degree is everything.”

The Bishop of Salisbury, the Rt Revd Nick Holtam, who leads on environment issues for the Church of England, said action needed to be taken to care for God’s creation. He said on Monday: “The evidence published by the IPCC today shows that the risk level of climate change is now critical. Ours is the first generation to know and understand this, and probably the last to be able to do something meaningful towards climate justice.

“For Christians, striving to safeguard the integrity of creation, and sustaining and renewing the life of the earth, is at the heart of what we believe. We have a narrow window now to act if we are to protect God’s creation for generations to come — as individuals, communities and as a global family.”

He challenged the UK Government to lead this change. “Building on the ten-year anniversary of the Climate Change Act, an ambitious UK Government would seek to be a world leader by committing to a target of net zero emissions by 2050.”

Last week, Christian Aid released a report showing that some of the biggest cities in the world including Houston, Shanghai, Jakarta, and London are in danger of being flooded if sea levels continue to rise at the current rate.

Joe Ware is a journalist at Christian Aid. Read this week’s special environmental report in the Church Times, out today. Listen to the Church Times Podcast on the environment here: