Global temperature rise set to cross 1.5-degree Celsius threshold: UN

Image for representational purpose only. Photo Courtesy: AFP

Amid growing concerns about climate change and global warming not only in India but across the world, along with the recent Nepal flash flood, a new report released by the United Nations (UN) on Wednesday, September 2, has revealed that global temperature rise is set to cross the 1.5-degree Celsius threshold, likely within the next few years, intensifying extreme weather, ecosystem loss and submersion of small island developing nations.

The report called "Limiting Overshoot" has been released by the UN Environment Programme (UNEP) and has emphasised the need for immediate and sustained cuts to greenhouse gas emissions.

"Global temperature rise is set to cross 1.5 degrees Celsius, likely within the next few years, pushing climate risks and impacts to increasingly dangerous heights, but it is still possible to bring temperatures down and achieve global goals in the Paris Agreement," the report said.

The 1.5 degrees Celsius was a safe temperature threshold that was agreed upon at the 2015 Paris Climate Agreement on December 12, that was adopted by 195 countries to keep it well below the 2 degree Celsius limit to deal with global warming due to the burning of coal, oil and gas. The world is now at 1.4 degrees Celsius above pre-industrial levels, some scientists have calculated. The measure is based on a 20-year average, rather than a single year's temperatures.

Now, above that mark, the risks and impacts will intensify with every extra fraction of a degree and every year, the report adds. The expected impacts of the increase in temperature include intensified extreme weather, ecosystem loss, and submersion of small island developing states, and low-lying coastal cities, it said.

The UN report also identified an "overshoot, peak, and decline" pathway as the best remaining option to minimise the magnitude and duration of the overshoot and to try to return to below 1.5 degrees Celsius as soon as possible.

In a statement, UN Secretary-General Antonio Guterres said, "This summer's scorching heat, raging wildfires and deadly floods are a warning of what lies ahead. We must make the overshoot above 1.5 degrees as small and short as possible. That demands an overshoot of ambition."

There is a need to minimise peak temperature rise through immediate and sustained cuts to greenhouse gas emissions, including methane, on the road to net-zero, said the report.

Moreover, even as the temperatures rise, the report said it is important that they must be brought down through long-term net-negative emissions, with carefully governed Carbon Dioxide Removal (CDR), which is the process of removing carbon from the air and storing it through afforestation or other means, as an essential part of the mix.

It also said the most optimistic scenario has warming peaking at 1.8 degrees Celsius around mid-century if countries pursue ambitious climate goals, but that governments' current policies should push temperatures to 2.6 degrees Celsius above pre-industrial levels by 2100.

So instead of preventing warming of 1.5 degrees, now the U.N. said it wants policymakers to "prepare for and navigate a future'' in which the globe crosses that limit and then corrects course and cools temperatures.

Inger Andersen, who is the executive director of UNEP, said, "Now is the time we must double down on climate action. We can -- and must -- get on the right path. By cutting greenhouse gas emissions, strengthening resilience and adaptation, and ensuring exceedance of 1.5 degrees Celsius is as small and short as possible."

He added, ""Let's be very clear, 1.5 target is still the goal. But now we need to approach it differently from above."

(With inputs from PTI and AP)