Nairobi — Climate scientists have rung the alarm about the urgent need for drastic environmental action to keep global warming from exceeding 1.5°C. The Special Report on Global Warming of 1.5ºC launched by the Intergovernmental Panel on Climate Change today cites the likely unprecedented environmental challenges the world needs to prepare for if global warming continues to increase at the current rate, and underscores the dramatic difference 0.5 ºC will make on future projections.
Hot extremes and periods with heavy rains and droughts are expected to increase as global temperatures continue to rise. While the world is already witnessing the impacts of an 1.0°C increase above pre-industrial levels, taking drastic measures to keep further global warming to a minimum will be vital: by 2100, global mean sea level rise is projected to be around 10 centimetres lower with global warming of 1.5°C compared to 2°C, and impacts on biodiversity and ecosystems, including species loss and extinction, are also projected to be significantly more manageable if temperature rise is curtailed.
"The science shows us that limiting warming will help avert huge costs to agriculture, to human health and biodiversity. It shows us that significant climate action is an investment worth making," Erik Solheim, Head of UN Environment said. "But at the same time, we need to go further. The commitments made under the Paris Agreement are now clearly not quite good enough. What we need is a race to the top."
Limiting global warming to 1.5ºC would require rapid, far-reaching and unprecedented changes in all aspects of society, including the way we manage our energy, industry, buildings, transport, and cities. Technologies to climate-proof buildings and construction exist and are cost-efficient, and more countries, cities and companies take on zero-emission building targets.
To stay within 1.5°C, global net CO2 emissions caused by human activity should decline by about 45% from 2010 levels by 2030, reaching 'net zero' around 2050, balancing emissions by removing CO2 from the atmosphere.
The Paris Agreement adopted by 195 nations at the 21st Conference of the Parties to the UNFCCC in December 2015 included the aim of strengthening the global response to the threat of climate change by "holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels."
As part of the decision to adopt the Paris Agreement, the IPCC was invited to produce, in 2018, a Special Report on global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways. The IPCC accepted the invitation, adding that the Special Report would look at these issues in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty.
"The good news is that we're starting to see significant shifts," Solheim further said. "Renewables can beat out fossil fuels on price. More and more people are also demanding action on air pollution in urban areas, which also happens to be caused by some of the same drivers of climate change. The whole notion that ambitious climate action is bad for the economy has been shown to be rubbish. Quite the contrary, it's been shown to be good for business. So the business and political case for action is already there. That means there are really no excuses."
The Special Report on Global Warming of 1.5ºC is the first in a series of Special Reports to be produced in the IPCC's Sixth Assessment Cycle. Next year the IPCC will release the Special Report on the Ocean and Cryosphere in a Changing Climate, and Climate Change and Land, which looks at how climate change affects land use.