The world faces unavoidable and worsening climate hazards over the next two decades as global temperatures are driven up by human activity, with "irreversible impacts" on humans and ecosystems expected even if the global economy achieves the unprecedented feat of only marginally overshooting the 1.5 degrees Celsius temperature goal agreed by governments.
Meanwhile, worst case scenarios where temperatures spiral past the 2C goal set in the Paris Agreement could result in widespread loss of productive agricultural land, every second known plant or animal species threatened and catastrophic socio-economic impacts as countries wrestle with rising sea levels, floods, droughts, deadly heatwaves, food shortages and migration.
That is the stark warning set out in a landmark report on climate impacts published Monday by the Intergovernmental Panel on Climate Change (IPCC), which has sounded the alarm that the impacts of climate change on humans and nature are more acute and happening faster than anticipated in previous assessments.
The Working Group II analysis published this week — the first report on the impact of climate change from IPCC scientists in eight years — notes that climate change is already affecting billions of people around the world and warns these impacts are set to intensify over the coming years as global temperatures continue to accelerate.
Adaptation and mitigation must be pursued with equal force and urgency. That's why I have been pushing to get to 50% of all climate finance for adaptation.
The findings highlight how human-induced climate change — alongside deforestation, pollution and land use change — is hampering nature's ability to provide services essential to human life, such as coastal protection, food supply or climate regulation through the capture and storage of carbon from the atmosphere.
It notes that increased heatwaves, droughts and floods are driving mass mortalities in species such as trees and corals, with these extreme weather events setting off a chain of cascading impacts that have exposed millions of people to acute food and water insecurity, especially in Africa, Asia, Central and South America, as well as the Arctic and on small islands.
Hoesung Lee, chair of the IPCC, said the findings were a "dire warning" about the consequences of inaction on climate change. "It shows that climate change is a grave and mounting threat to our well-being and a healthy planet," he said. "Our actions today will shape how people adapt and nature responds to increasing climate risks."
The report calls for drastic and concerted action to bring down emissions, noting that meeting the Paris Agreement's target of capping global temperature rise at 1.5C will be instrumental in reducing the impacts of climate change on both humans and animals. It includes the IPCC's strongest call yet for nature protection to be placed at the heart of efforts to tackle climate change, warning that safeguarding and strengthening nature is critical to securing a livable future.
"Healthy ecosystems are more resilient to climate change and provide life-critical services such as food and clean water," said IPCC Working Group II co-chair Hans-Otto Pörtner. "By restoring degraded ecosystems and effectively and equitably conserving 30 to 50 percent of Earth's land, freshwater and ocean habitats, society can benefit from nature's capacity to absorb and store carbon, and we can accelerate progress towards sustainable development, but adequate finance and political support are essential."
While conceding the scale and scope of global action to reduce climate risks has picked up, the report warns these efforts are unevenly spread around the world and nowhere near commensurate to the scale of the crisis. The window for action is narrowing, it warns, with every fraction of a degree of warming set to make adaptation efforts more difficult and expensive, it notes.
"The scientific evidence is unequivocal: Climate change is a threat to human well-being and the health of the planet," said Pörtner. "Any further delay in concerted global action will miss a brief and rapidly closing window to secure a livable future."
The report confirms global temperatures are currently 1.1C above pre-industrial levels, with temperature rise projected to overshoot the 1.5C target recommended by climate scientists over the next 20 years, despite growing numbers of national and corporate net-zero targets. A separate report from IPPC scientists last summer warned that global warming is on track to far exceed 2C this century, unless rapid and deep reductions in greenhouse gas emissions occur in the coming decades.
The IPCC today warned that even a temporary overshoot of the Paris Agreement's 1.5C target will cause dangerous climate impacts that will hurt humans and animals, some of which will be irreversible. "If global warming transiently exceeds 1.5C in the coming decades or later, then many human and natural systems will face additional severe risks, compared to remaining below 1.5C," the report states. "Depending on the magnitude and duration of overshoot, some impacts will cause release of additional greenhouse gases and some will be irreversible, even if global warming is reduced."
With 70 percent of the world's population expected to live in cities by 2050, the report pays special attention to the risks global warming presents to urban populations, and the ways that cities can be developed to adapt to and mitigate against climate risks.
It notes that extreme weather events and sea-level rise around the world has caused havoc with urban energy and transportation systems, as well as property and critical infrastructure, and calls for policymakers to work with all stakeholders to scale solutions that can make cities more resilient in a warming world.
"Together, growing urbanization and climate change create complex risks, especially for those cities that already experience poorly planned urban growth, high levels of poverty and unemployment and a lack of basic services," said IPCC Working Group II co-chair Debra Roberts. "But cities also provide opportunities for climate action — green buildings, reliable supplies of clean water and renewable energy, and sustainable transport systems that connect urban and rural areas can all lead to a more inclusive, fairer society."
But the IPCC has warned that delivering infrastructure and services that are resilient to climate change is already a challenge at current levels of warming and is set to become more difficult as temperatures and extreme weather risks intensify. Climate resilience will become impossible in some regions if temperature rise exceeds 2C, the report warns.
The Working Group II report put together by 270 scientists from 67 countries for the U.N. body is the second installment of a three-part series that collectively make up the sixth assessment cycle of the IPCC, otherwise known as the Sixth Assessment Report (AR6). The first installment, published in August, looked at the physical science and trajectory of climate change, whereas the third part, to be published in April, will set out potential strategies and the associated costs for trying to tackle the climate crisis.
Companies must prepare themselves for the impacts of climate change and show that they have the ability to adapt, be it through resilient supply chains or business models, efforts toward adaptation are now the minimum requirement for survival.
United Nations Secretary-General Antonio Guterres said the findings revealed how "people and planet are getting clobbered by climate change."
"Nearly half of humanity is living in the danger zone, now," he said. "Many ecosystems are at the point of no return, now. Unchecked carbon pollution is forcing the world's most vulnerable on a frog march to destruction, now. The facts are undeniable. This abdication of leadership is criminal. The world's biggest polluters are guilty of arson of our only home."
Guterres called on policymakers to deliver a "prompt, well-managed transition to renewables," arguing it was the "only pathway to energy security, universal access and the green jobs our world needs."
"Fossil fuels are a dead end — for our planet, for humanity and yes, for economies," he added.
Guterres added that scaling up investments in adaptation would be "essential for survival" and called on developed nations to ensure funding flows allocated to projects that delivered emissions reduction were matched by investments that enabled nature and humans to prepare for escalating climate impacts. "Adaptation and mitigation must be pursued with equal force and urgency," he said. "That's why I have been pushing to get to 50 percent of all climate finance for adaptation."
Kate Blagojevic, head of climate at Greenpeace UK, said the findings highlighted the need for "recognition and financial support for the loss and damage already being faced by so many communities on the front line of the climate crisis."
"Climate change isn't just a time bomb we're setting for future generations, it can be documented right now in the lives and livelihoods lost and in irreparable damage caused to our natural world," she said. "Industrialized nations owe the means to take real action to those communities already staring down the barrel of this crisis."
Blagojevic said the UK had a responsibility as COP president to push the international community to respond to the report's warnings. "It's time to stop and reverse deforestation and commit to protecting 30 percent of our oceans by 2030," she said. "We have to accelerate renewable energy and plough forward with energy efficiency measures. And we must reduce meat and dairy consumption in high-consuming countries like the UK."
And Nicolette Bartlett, chief impact officer at investor-backed climate disclosure initiative CDP, said the IPCC's stark findings should act as a major catalyst for action among the business and governments in high-emitting economies most responsible for climate change.
"In addition to its impact on people and planet, climate change is the single greatest risk to the global economy," she said. "Companies must prepare themselves for the impacts of climate change and show that they have the ability to adapt, be it through resilient supply chains or business models, efforts toward adaptation are now the minimum requirement for survival. Inaction is a foolish business risk no company can afford. Measuring and managing environmental risks through disclosure will help to build resilience and plan for the future. There are a wealth of frameworks and standards to guide corporates through that process in line with best practice."