The UN Intergovernmental Panel on Climate Change (IPCC) issued its latest report on the climate crisis on Monday under the title of AR6 Synthesis Report: Climate Change 2023 summarising five years of the state of knowledge on climate change, its widespread impacts and risks, and climate mitigation, and adaptation efforts.

The report recognises the interdependence of climate, ecosystems and biodiversity, and human societies, as well as the close linkages between climate-change adaptation, mitigation, ecosystem health and sustainable development.

According to the report, a summary of the IPCC’s sixth Assessment Cycle reports published between 2018 and 2023, global greenhouse gas (GHG) emissions have continued to increase and led to temperatures 1.1 °C higher in 2011-2020 than those recorded between 1850 and 1900 as a result of unsustainable energy and land use, lifestyles, and patterns of consumption and production across regions.

Global surface temperatures have increased faster since 1970 than in any other 50-year period over at least the last 2,000 years, the report says.

Despite progress on climate action policies and legislation, the report said it was likely that global warming will exceed 1.5 °C during the 21st century based on current nationally determined contributions (NDCs) by countries signatory to the Paris Agreement, a legally binding international treaty adopted in 2015 by 196 countries that agreed to limit global warming to well below 2 °C.  

More than half (58 per cent) of historical cumulative net CO2 emissions from 1850 to 2019 had occurred between 1850 and 1989, the report said, and about 42 per cent had occurred between 1990 and 2019. In 2019, atmospheric CO2 concentrations were higher than at any time in at least the last two million years, and concentrations of methane and nitrous oxide were higher than at any time in at least 800,000 years.

“It is unequivocal that human influence has warmed the atmosphere, ocean, and land,” the report said, adding that the average rate of sea-level rise was 1.3 (0.6 to 2.1) mm/year between 1901 and 1971, increasing to 1.9 (0.8 to 2.9) mm/year between 1971 and 2006, and further increasing to 3.7 (3.2 to 4.2) mm/year between 2006 and 2018.

Human influence was very likely the main driver of these increases since at least 1971, according to the report, as evidence of observed changes in extremes such as heat waves, heavy precipitation, droughts, tropical cyclones, and in particular their attribution to human influence has further strengthened.

“Approximately 3.3 to 3.6 billion people live in contexts that are highly vulnerable to climate change. Human and ecosystem vulnerability are interdependent,” the report said.

Increasing weather and extreme climatic events have exposed millions of people to acute food insecurity and reduced water security, with the largest adverse impacts observed in locations and communities in Africa, Asia, Central and South America, small islands and the Arctic, and for indigenous peoples worldwide, along with small-scale food producers and low-income households.

According to the report, between 2010 and 2020, human mortality from floods, droughts and storms was 15 times higher in highly vulnerable regions compared to regions with very low vulnerability. It added that climate change has caused substantial damages, and increasingly irreversible losses, in terrestrial, freshwater, coastal and open ocean ecosystems, with hundreds of local losses of species being driven by increases in mass mortality events recorded on land and in the ocean.

Moreover, impacts on some ecosystems are approaching irreversibility such as the impacts of hydrological changes resulting from the retreat of glaciers, or the changes in some mountain and Arctic ecosystems driven by permafrost thaw.

“Climate change has reduced food security and affected water security, hindering efforts to meet Sustainable Development Goals [SDGs],” the report stressed.

In urban areas, it added, observed climate change has caused adverse impacts on human health, livelihoods, and key infrastructure. Heat extremes have intensified in cities. “Urban infrastructure, including transportation, water, sanitation and energy systems have been compromised by extreme and slow-onset events, with resulting economic losses, disruptions of services and negative impacts to well-being.”

On combating the effects of climate change and global warming, the report said that adaptation planning and implementation had progressed across all sectors and regions, with documented benefits and varying effectiveness.

Despite such progress, adaptation gaps exist and will continue to grow at current rates of implementation, according to the report, and hard and soft limits to adaptation have been reached in some ecosystems and regions.

“Maladaptation is happening in some sectors and regions. Current global financial flows for adaptation are insufficient for, and constrain implementation of, adaptation options, especially in the developing countries,” it said.

The report said that key barriers to adaptation are limited resources, lack of private-sector and citizen engagement, the insufficient mobilisation of finance (including for research), low climate literacy, lack of political commitment, limited research and/or slow and low uptake of adaptation science, and a low sense of urgency.

There are widening disparities between the estimated costs of adaptation and the finance allocated to adaptation, the report says, adding that adaptation finance has come predominantly from public sources and a small proportion of globally tracked climate finance was targeted to adaptation and an overwhelming majority to mitigation.

On mitigation, the report said that policies addressing this have expanded over the last few years. However, global GHG emissions in 2030 implied by nationally determined contributions announced by October 2021 make it likely that warming will exceed 1.5 °C during the 21st century and make it harder to limit warming below 2 °C.

“There are gaps between projected emissions from implemented policies and those from NDCs, and finance flows fall short of the levels needed to meet climate goals across all sectors and regions,” the report said.

Continued greenhouse gas emissions will lead to increasing global warming, the report warned, adding that every increment of global warming will intensify multiple and concurrent hazards.

On the other hand, deep, rapid, and sustained reductions in greenhouse gas emissions would lead to a discernible slowdown in global warming within around two decades and also to discernible changes in atmospheric composition within a few years, it said.

The report stressed that adaptation options that are feasible and effective today will become constrained and less effective with increasing global warming, as losses and damages will increase and additional human and natural systems will reach adaptation limits.

However, maladaptation can be avoided by flexible, multi-sectoral, inclusive, and long-term planning and the implementation of adaptation actions, with co-benefits to many sectors and systems, according to the report.

It says that near-term integrated climate action is urgent, as there is a rapidly closing window of opportunity to secure a livable and sustainable future for all.

Climate-resilient development integrates adaptation and mitigation to advance sustainable development for all, it said, and is enabled by increased international cooperation including improved access to adequate financial resources, particularly for vulnerable regions, sectors and groups, and inclusive governance and coordinated policies.

“The choices and actions implemented in this decade will have impacts now and for thousands of years,” the report said, adding that sustained mitigation and adaptation actions in this decade would reduce projected losses and damage for humans and ecosystems and deliver many co-benefits.

Similarly, prioritising equity, climate justice, social justice, inclusion and just transition processes can enable adaptation and ambitious mitigation actions and climate-resilient development, with the availability of political commitment, well-aligned multilevel governance, institutional frameworks, and enhanced access to finance and technology, as key to accelerate the widespread adoption of technologies and practices.

“If climate goals are to be achieved, both adaptation and mitigation financing would need to increase many-fold,” the report said, adding that there is sufficient global capital to close the global investment gaps and enhancing international cooperation to achieve this is possible through multiple channels.

* A version of this article appears in print in the 23 March, 2023 edition of Al-Ahram Weekly