Putting together the many climate studies published in 2019, scientists tell the UN climate summit in Mardrid that the world is very close to tipping points
On the day young climate activist Greta Thunberg arrived at the UN summit in Madrid and cornered much of the attention, the world’s scientists put together a “super summary” of the many climate reports that have been published recently, and concluded, “2019 is a bad year for the climate system, a bad year for humanity,” in the words of Johan Rockstrom of Future Earth.
“We have more evidence than ever before of the impacts that are hitting across communities in the entire world, we have more evidence than ever of the risks we’re facing, that we’re approaching potential tipping points, but in particular, when you put all this together, there is scientific support for declaring a state of climate emergency.”
The summary puts together reports from the Intergovernmental Panel on Climate Change (IPCC), the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the UN Environmental Programme, the World Meteorological Organisation and others.
Patricia Espinosa, Executive Secretary of the UN Framework Convention on Climate Change, promised, “I’ll be reminding all parties (national governments) and other groups, of course, of this report as they continue their negotiations. It serves as an important reminder of the need to significantly boost their climate ambition.”
National pledges made for the 2015 Paris agreement add up to a world nearly three degrees Celsius hotter than preindustrial times, whereas any warming beyond 1.5 C was going to be significantly harmful, and over 2 C, dangerous.
The 10 insights of the “super summary” are:
The world is not on track: Despite increasing drivers of reduced emissions, such as growth in green energy, institutions divesting from fossil fuels, and some countries phasing out coal power, the fossil industry is still growing and global leaders aren’t yet committing to the necessary emissions cuts. The world is not on track to reach the Paris Agreement.
Climate change is faster and stronger than expected: The pace of contemporary rise in greenhouse gas concentrations is unprecedented in climate history over the past 66 million years, and methane concentrations are now at a record high of 257% of preindustrial levels. Observations show signs of continuing warming. A global temperature rise to 1.5 degrees Celsius above preindustrial levels could be reached already in the year 2030, instead of 2040 as is the mean projection of IPCC. Sea-level rise is accelerating and is now three times higher than the average for the 20th century. Relatively stable components of the earth system also show signs of accelerated degradation, such as the Greenland and Antarctic ice sheets, which – if destabilised – could lead to severe, abrupt ice loss from ice-sheet margins and would thereby critically accelerate sea-level rise.
Climate change leaves no mountain summit behind: Mountains are at the forefront of climate change impact. Glaciers, snow, ice, and permafrost are diminishing in mountains, which will influence water availability and will increase natural hazards such as landslides and rockfalls, potentially affecting more than a billion people worldwide. Climate change will also irreversibly affect mountain ecosystems and their biodiversity, reducing the area of biodiversity hotspots, causing species to go extinct, and compromising the capacity of mountains to provide key ecosystem services. The world should recognise that indigenous and local knowledge in mountain regions plays a key role in conservation and management.
Forests are under threat, with global consequences: The world’s forests are a major carbon dioxide sink, absorbing about a third of anthropogenic carbon dioxide emissions. Yet human-driven forest fires have been reducing these sinks, and climate change globally amplifies wild forest fires. Increases in fires are observed in Western US and Alaska, Canada, Russia and Australia as a result of prolonged drought. Huge emissions have been observed from land changes in western Ethiopia and western tropical Africa. Loss of forests affects both the local and global climate. Fighting deforestation and encouraging reforestation, along with sustainable forest management and other natural climate solutions, are important and cost-effective options for reduced net emissions.
Weather extremes a “new normal” in 2019: Climate change is forcing the world to reconsider the notion of an extreme event. What was once considered unlikely or rare – both in terms of the intensity and frequency – is becoming part of a “new normal.” Record-breaking extreme weather and climate events have continued to dominate the headlines in 2019, with the impact of such events going beyond mere record setting and environmental damage: the material and human costs are especially high. Increasingly, societies will have to adapt to compound events, which can amplify the risk of severe impacts significantly, and cascading events, which do not leave enough time for societies to recover before the next extreme weather event happens. Persistent rainfall extremes and heatwaves, unusual weather patterns due to a changing jet stream in the northern hemisphere, as well as warmer and higher seas will all affect regions across the world in different ways. Ambitious mitigation can curb risks if we stay at 1.5 degrees Celsius warming, but regionally, dangerous levels will be reached.
Biodiversity – threatened guardian of earth’s resilience: Biodiversity on land, coral reefs, and fish populations will see losses between 14% and 99% at one to two degrees Celsius warming. At the same time, biodiversity is a key feature of stable ecosystems, providing – among many other services to humanity – carbon stocks and sinks and thereby guarding the earth system’s resilience against the disruption from anthropogenic carbon emissions. Therefore, it is urgent to put a halt to ecosystem degradation.
Climate change threatens food security and the health of hundreds of millions: Undernutrition will be the greatest health risk of climate change with declining agricultural productivity, particularly in drylands in Africa and high mountain regions of Asia and South America. In addition, increasing concentrations of carbon dioxide will reduce the nutritional quality of most cereal crops. Climate change is already affecting food production by reducing agricultural yields, especially in the tropics, and will increase loss and damage throughout the food system. Global fish stocks are set to further decline with climate change, and is an additional pressure on already declining stocks of fish and shellfish, important sources of human dietary protein and nutrients.
Most vulnerable and poor hardest hit by climate change: Failure to address and adapt to climate change will have disastrous consequences for hundreds of millions of people, mainly the very poorest, and will hinder development in developing countries. While all will be affected by climate change, the poor are more vulnerable to drought, flooding, high temperatures, and other natural disasters with low capacity to adapt. As the frequency of natural and climatic hazards increases, escaping poverty will be particularly difficult, even with progress on the UN Sustainable Development Goals (SDGs).
Equity and equality pivotal to successful climate change mitigation and adaptation: Social justice is an important factor for societal resilience in the face of climate change, vital for both local and global cooperation to facilitate mitigation and adaptation. High inequality has been identified as a contributing factor when resource depletion has driven civilisations to collapse in the past, and threatens the ability of the current civilisation to survive climate change and other environmental changes. The success of climate policy also depends on social acceptance, with justice, fairness, and the equitable distribution of costs important for public support of policy and avoiding nationalist sentiments.
Time may have come for social tipping points on climate action: Public opinion polls indicate that an increasing number of citizens in various countries are seriously concerned about climate change, and recent massive civil protests are getting close to the thresholds where one could expect “tipping” of some socio-economic systems. However, policy measures need to accompany behavioural change – and deep and long-term transformations driven by a great diversity of actors are needed to meet the Paris Agreement and the SDGs.