The year 2023 shattered climate records again, since it was the hottest year in recorded history.
It was also the first year on record with all days over 1°C warmer than the pre-industrial period, when the average temperature was 1.45 °C above the pre-industrial levels, even briefly surpassing them by more than 2°C.
Greenhouse gases (carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, water vapour and ozone) are part of Earth’s atmosphere. The gases are crucial in the natural greenhouse effect that maintain the stability of Earth’s atmosphere and keep “an average temperature of 15 °C” (2, 4). The increase of greenhouse gas levels have disrupted the balance, which is driving the heating of the atmosphere resulting in climate warming and speeding up the planetary crisis.
In 2023, the atmospheric concentrations of greenhouse gases carbon dioxide and methane continued to increase and “reached record levels 419 ppm and 1902 ppb respectively” (4). Furthermore, in March 2024 CO2 level was again higher, reaching 425 ppm.
Greenhouse gas levels are driving the heating the atmosphere resulting in Climate Warming. And climate warming plays out through heating the atmosphere and the oceans. In addition, climate warming plays out in extreme weather events such as heatwaves, drought, forest fires, extreme rainfall and floods.
Data source: Reconstruction from ice cores. Credit: NOAA
Global surface air temperature increase relative to the average for 1850-1900, the designated pre-industrial reference period, based on several global temperature datasets shown as 5-year averages since 1850 (left) and as annual averages since 1967 (right). Credit: C3S/ECMWF.
Surface air temperature anomaly for 2023 relative to the average for the 1991-2020 reference period. Data source: ERA5. Credit: C3S/ECMWF.
Greenhouse gas levels are driving the heating of the atmosphere resulting in Climate Warming.
The Intergovernmental Panel on Climate Change (IPCC) report states that the policies that have been implemented by 2020 lead to 2.2-3.5°C global warming by 2100 with medium confidence. Moreover, climate warming will continue to increase without “deep, rapid and sustained” greenhouse gas emission reductions (18).
HEATING OCEANS
In 2023 Ocean heat was unprecedented. “Global average sea surface temperatures (SSTs) remained persistently and unusually high, reaching record levels for the time of year from April through December” (4). Marine heatwaves harmed ecosystems “around the globe, including in parts of the Mediterranean, Gulf of Mexico and the Caribbean, Indian Ocean and North Pacific, and much of the North Atlantic” (4). Climate warming “affects marine life negatively mainly through its ‘deadly trio’ of making seawater warmer, more acidic, and less rich in oxygen” (13). In addition, the thermal expansion of the sea water is also affecting the sea level rise (9).
MELTING ICE
In 2023 Antarctic sea ice was record low (2, 4), and glacier retreat was the worst on record, resulting in the accelerating melting and sea level rise (2). “The ice sheet of west Antarctica would push up the oceans by 5 metres if lost completely” (9). Many millions “live in coastal cities that are vulnerable to sea level rise, from New York to Mumbai to Shanghai, and more than a third of the global population lives within 62 miles (100km) of the coast” which will result in more forced migration in the future (9).
WILDFIRES
Devastating fires are becoming more frequent and widespread (1, 4). In 2023 there were wildfires in Greece, Italy, Spain, Portugal, Algeria, Tunisia and Canada causing casualties as well as environmental and economic damage (1). Wildfires effect also in the carbon emissions, estimated “global wildfire carbon emissions in 2023 increased by 30% with respect to 2022 driven largely by persistent wildfires in Canada” (4).
DROUGHT
Alarming changes in the entire global water cycle have become apparent (8). Drought has afflicted 1.84 billion people, and in 2023 countries such as Uruguay, Canada, Spain, Italy, United Kingdom, Sri Lanka, India and Indonesia have reported drought. Drought affects especially the poorest and most vulnerable people, especially children, and “85% of people affected by droughts live in low or middle-income countries” (8). In addition, 4.7% are exposed to severe or extreme drought. Drought has impacts on well-being, agriculture, electricity production, and causes famine, forced migration, as well as effects on global crop markets. Drought creates suffering, uncertainty and instability which have global effects also in geopolitics and economy.
RAINFALL AND FLOODS
Extreme rainfall and flooding causes devastation. In 2023 flooding was reported in locations such as Hong Kong, Libya, Greece, Turkey, Bulgaria, Spain, Taiwan, Brazil and the United States. The poor and vulnerable suffer most. One of the most tragic floods was in Derna, Libya, killing more than 11000 people and leaving thousands missing. Floods can cause deaths also after the incident, raising the risk of dying increased and persisted for up to 60 days, increasing by 2.1% for all-cause deaths, 2.6% for cardiovascular deaths, and 4.9% for respiratory deaths. Extreme rainfall and drought also creates forced migration, 98% of the 32.6 million new disaster displacements in 2022 were the result of weather-related hazards such as storms, floods and droughts.
PLANETARY CRISIS
Climate warming is also speeding up the planetary crisis. Six out of nine boundaries of the Earth System are now over the safe operating limit. Each area of the Earth system is interconnected to other areas of the system, resulting in cascading effects on the whole. Therefore, when searching for solutions, we cannot focus only on one area such as climate warming or emissions.
“While transgressing a boundary is not equivalent to drastic changes happening overnight, together they mark a critical threshold for increasing risks to people and the ecosystems we are part of”
– Stockholm Resilience Center
The climate, water cycle, ecosystems and biodiversity are all interconnected, and human belief systems, knowledge, behaviour, societies and cultures have close links to the system health. Resulting in our ability to influence climate change adaptation and mitigation, and sustainable development.
The 2023 update to the Planetary boundaries. Licensed under CC BY-NC-ND 3.0. Credit: “Azote for Stockholm Resilience Centre, based on analysis in Richardson et al 2023”.
In the context of climate warming, the limit of the safe operating space for the Earth System is 1.5°C. But it is not a magical number that would guarantee of avoiding extreme, global warming effects anywhere. Instead 1.5°C is a “defense line” (6). If the world can keep below 1.5°C threshold, “it potentially could avoid the more extreme and irreversible climate effects that would occur with a 2°C increase, and for some places, an even smaller increase than that” (6).
“1.5°C is a defense line. The lower the target for an increase in temperature, the lower the risks of climate impacts.”
– MIT
In order to “hold the planet’s long-term average temperature below the 1.5-degree threshold, the world will have to reach net zero emissions by the year 2050, according to the IPCC. This means that in terms of the emissions released by the burning of coal, oil, and natural gas, the entire world will have to remove as much as it puts into the atmosphere” (6). However, already during 2023 the average temperatures reached 1,45 degrees of Celsius and the atmosphere seems to be warming more rapidly.
For example, the European Union, in line with the best available science, has agreed on an emission reduction of 55% by 2030 – which is now just 5 years away. The challenge is clear. We need to accelerate the green transition.
“Earth is a living planet, so the consequences are impossible to predict.”
-Sarah Cornell
Our planet, our children nor the future generations can wait. The cost of inaction is higher than action.
But there is still hope. There are multiple “opportunities for transformative action which are effective, feasible, just and equitable using concepts of systems transitions and resilient development pathways” (18). “Deep, rapid and sustained reductions of greenhouse gas emissions would lead to improvements in air quality within a few years and global surface temperature after 20 years” (18).
Development strategies that have a systemic view on human societies, ecosystems, climate and biodiversity are the most effective, for example implementation across sectors, and conscious ecosystem innovation.
REFERENCES
- European Space Agency: https://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-3/Counting_wildfires_across_the_globe
- World meteorological organization: The state of the climate in 2023 https://youtu.be/ES7eKWRRJ0o
- World fire atlas: https://s3wfa.esa.int/viewer
- Copernicus climate change service, Global climate highlights 2023: https://climate.copernicus.eu/copernicus-2023-hottest-year-record#:~:text=European%20temperature%20highlights%3A&text=Temperatures%20in%20Europe%20were%20above,second%2Dwarmest%20winter%20on%20record
- Global climate highlights 2023: https://climate.copernicus.eu/global-climate-highlights-2023
- Why 1.5 degrees of Celsius? https://news.mit.edu/2023/explained-climate-benchmark-rising-temperatures-0827
- Stockholm resilience center: All planetary boundaries mapped out for the first time, six of nine crossed
- Global Drought Snapshot 2023: https://www.unccd.int/sites/default/files/2023-12/Global%20drought%20snapshot%202023.pdf
- https://www.theguardian.com/environment/2023/oct/23/rapid-ice-melt-in-west-antarctica-now-inevitable-research-shows
- What we learned about floods 2023 (www.preventionweb.net)
- Global rain flooding climate crisis (cnn.com)
- Outside planetary boundary novel entities (www.sei.org)
- Warming acidification dropping oxygen levels (www.eea.europa.eu)
- IPCC report AR2
- IPCC report AR3
- IPCC, 2007: Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, A. (eds.)]. IPCC, Geneva, Switzerland, 104 pp. https://www.ipcc.ch/report/ar4/syr/
- IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp. https://www.ipcc.ch/report/ar5/syr/
- IPCC, 2023: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, H. Lee and J. Romero (eds.)]. IPCC, Geneva, Switzerland, 184 pp., doi: 10.59327/IPCC/AR6-9789291691647. https://www.ipcc.ch/report/ar6/syr/
- https://www.cambridge.org/core/journals/cambridge-prisms-coastal-futures/article/population-development-as-a-driver-of-coastal-risk-current-trends-and-future-pathways/8261D3B34F6114EA0999FAA597D5F2E2
- https://www.ipcc.ch/site/assets/uploads/2017/08/AR5_Uncertainty_Guidance_Note.pdf