Current targets to control climate change are simply not enough to stop a catastrophic rise in global temperatures, scientists warned ahead of the UN climate action summit

Global emissions have to be reduced aggressively to avoid catastrophic climate change (Photo by Rebecca Humann)
Climate change has been accelerating in the past several years, with carbon dioxide levels in the atmosphere rising faster than ever, along with sea level rise and shrinking ice sheets, top climate scientists warned in a report published on the eve of the United Nations Climate Action Summit in New York on Monday.
The targets by the world’s nations to rein in climate change need to be tripled if the rise in global temperatures is to be limited to 2 degrees Celsius compared with preindustrial times that was agreed upon in the 2015 Paris climate pact, said the United in Science report released on Sunday. It warned that present plans would see a rise in average temperatures of between 2.9 and 3.4 degrees Celsius by the end of the 21st century, which is likely to lead to “catastrophic” climate change.
“Average global temperature for 2015-19 is on track to be the warmest of any equivalent period on record. It is currently estimated to be 1.1 degree Celsius above preindustrial (1850-900) times and 0.2 degree warmer than 2011-15,” the report said. “Observations show that global mean sea level rise is accelerating and an overall increase of 26% in ocean acidity since the beginning of the industrial era.”
Worldwide demonstrations
Millions of mostly young people took to the streets on Friday in the biggest ever worldwide display to call attention to the climate crisis ahead of the action summit called by the United Nations Secretary-General Antonio Guterres. See: Indian youth marches to demand life
There are major benefits to limiting global warming to 1.5 degrees Celsius above preindustrial levels, but doing so will need “rapid, far reaching and unprecedented changes in all aspects of society,” the Intergovernmental Panel on Climate Change (IPCC) said in a special report last year. See: Change world to control climate change, say experts
Not enough governments are on track to cut carbon emissions, UN Environment said in its 2018 emissions gap report. Preliminary findings from the 2019 gap report indicate that greenhouse gas emissions continued to rise in 2018, said the United in Science report.
The report highlighted the urgency of fundamental socioeconomic transformation in key sectors such as land use and energy in order to avert dangerous global temperature increase with potentially irreversible impacts. “It highlights the urgent need for the development of concrete actions that halt global warming and the worst effects of climate change,” the Science Advisory Group to the action summit said in a statement. The group is co-chaired by Petteri Taalas, Secretary-General of the World Meteorological Organisation, and Leena Srivastava, former Vice Chancellor of TERI School of Advanced Studies.
Glaring gap
The report shows the growing gap between agreed targets to tackle global warming and the actual reality. It said that widespread and long-lasting heatwaves, record-breaking fires and other devastating events such as tropical cyclones, floods and drought have had major impacts on socioeconomic development and the environment.
The levels of the main long-lived greenhouse gases — carbon dioxide, methane and nitrous oxide — have reached new highs, it said. “In 2018, global CO2 concentration was 407.8 parts per million (ppm), 2.2 ppm higher than 2017. Preliminary data from a subset of greenhouse gas monitoring sites for 2019 indicate that CO2 concentrations are on track to reach or even exceed 410 parts per million (ppm) by the end of 2019,” the report said.
Carbon dioxide emissions grew 2% and reached a record high of 37 billion tonnes in 2018. There is still no sign of a peak in global emissions, even though they are growing slower than the global economy, the report said. “Current economic and energy trends suggest that emissions will be at least as high in 2019 as in 2018,” it said. “Global GDP is expected to grow at 3.2% in 2019, and if the global economy decarbonised at the same rate as in the last 10 years, that would still lead to an increase in global emissions.”
Global emissions are not estimated to peak by 2030, let alone by 2020, if current climate policies and ambition levels of the Nationally Determined Contributions (NDCs) are maintained, the report said. NDCs are reductions in greenhouse gases agreed to by countries under the UN Framework Convention on Climate Change.
“Implementing unconditional NDCs, and assuming that climate action continues consistently throughout the 21 st century, would lead to a global mean temperature rise between 2.9 degrees and 3.4 degrees Celsius by 2100 relative to preindustrial levels,” the report said.
If NDC ambitions are not increased immediately and backed up by action, exceeding the 1.5 degrees Celsius goal aimed in the Paris Agreement can no longer be avoided, it said. “If the emissions gap is not closed by 2030, it is very plausible that the goal of a well-below 2 degrees Celsius temperature increase is also out of reach.”