Climate science is clear: we are heading in the wrong direction, according to a new multi-agency report coordinated by the World Meteorological Organization (WMO), which highlights the huge gap between aspirations and reality. Without much more ambitious action, the physical and socioeconomic impacts of climate change will be increasingly devastating, it warns.
The report, United in Science, shows that greenhouse gas concentrations continue to rise to record highs. Fossil fuel emission rates are now above pre-pandemic levels after a temporary drop due to lockdowns. The ambition of emissions reduction pledges for 2030 needs to be seven times higher to be in line with the 1.5 °C goal of the Paris Agreement
The past seven years were the warmest on record. There is a 48% chance that, during at least one year in the next 5 years, the annual mean temperature will temporarily be 1.5°C higher than 1850-1900 average. As global warming increases, “tipping points” in the climate system can not be ruled out.
Cities that host billions of people and are responsible for up to 70% of human-caused emissions will face increasing socio-economic impacts. The most vulnerable populations will suffer most, says the report which gives examples of extreme weather in different parts of the world this year.
“Floods, droughts, heatwaves, extreme storms and wildfires are going from bad to worse, breaking records with alarming frequency. Heatwaves in Europe. Colossal floods in Pakistan. Prolonged and severe droughts in China, the Horn of Africa and the United States. There is nothing natural about the new scale of these disasters. They are the price of humanity’s fossil fuel addiction,” said UN Secretary-General António Guterres.
“This year’s United in Science report shows climate impacts heading into uncharted territory of destruction. Yet each year we double-down on this fossil fuel addiction, even as the symptoms get rapidly worse,” Mr Guterres said in a video message.
“Climate science is increasingly able to show that many of the extreme weather events that we are experiencing have become more likely and more intense due to human-induced climate change. We have seen this repeatedly this year, with tragic effect. It is more important than ever that we scale up action on early warning systems to build resilience to current and future climate risks in vulnerable communities. That is why WMO is spearheading a drive to ensure Early Warnings for All in the next five years,” said WMO Secretary-General Prof. Petteri Taalas.
United in Science provides an overview of the most recent science related to climate change, its impacts and responses. The science is clear – urgent action is needed to mitigate emissions and adapt to the changing climate, says the report. It includes input from WMO (and its Global Atmosphere Watch and World Weather Research Programmes); the UN Environment Programme, the UN Office for Disaster Risk Reduction, the World Climate Research Programme, Global Carbon Project; UK Met Office, and the Urban Climate Change Research Network. It includes relevant headline statements from the Intergovernmental Panel on Climate Change’s Sixth Assessment Report.
Greenhouse Gas (GHG) Concentrations in the Atmosphere
WMO Global Atmosphere Watch (GAW)
Levels of atmospheric carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) continue to rise. The temporary reduction in CO2 emissions in 2020 during the pandemic had little impact on the growth of atmospheric concentrations (what remains in the atmosphere after CO2 is absorbed by the ocean and biosphere).
Data from all global locations, including flagship observatories at Mauna Loa (Hawaii, USA) and Cape Grim (Tasmania, Australia) indicate that levels of CO2 continued to increase in 2021 and 2022. In May 2022, CO2 concentration at Mauna Loa reached 420.99 ppm (419.13 ppm in 2021) and Cape Grim 413.37 ppm (411.25 ppm in May 2021).
Global Greenhouse Gas Emissions and Budgets
Global Carbon Project
Global fossil CO2 emissions in 2021 returned to the pre-pandemic levels of 2019 after falling by 5.4% in 2020 due to widespread lockdowns. Preliminary data shows that global CO2 emissions in 2022 (January to May) are 1.2% above the levels recorded during the same period in 2019, driven by increases in the United States, India and most European countries.
Despite a strong fluctuation in global emissions over the past two and a half years, fossil CO2 emissions fell signiﬁcantly in 23 countries (many European countries, Japan, Mexico and the USA) during the pre-pandemic decade of 2010–2019.
A quarter of GHG emissions from land-use change are associated with the trade of food between countries, of which more than three quarters are due to land clearing for agriculture, including grazing.
State of the Global Climate: 2018–2022
World Meteorological Organization (WMO)
The most recent seven years, 2015 to 2021 were the warmest on record. The 2018–2022 global mean temperature average (based on data up to May or June 2022) is estimated to be 1.17 ± 0.13 °C above the 1850–1900 average. A La Niña event has had a slight cooling effect on temperatures in 2021/22 but this will be temporary.
Around 90% of the accumulated heat in the Earth system is stored in the ocean, the Ocean Heat Content for 2018–2022 was higher than in any other 5-year period, with ocean warming rates showing a particularly strong increase in the past two decades.
Global Climate Predictions for 2022–2026
Met Office, UK / WMO / World Climate Research Programme
The annual mean global near-surface temperature for each year from 2022-2026 is predicted to be between 1.1 °C and 1.7 °C higher than pre-industrial levels (1850-1900).
The likelihood of the annual mean global near-surface temperature temporarily exceeding 1.5 °C above pre-industrial levels for at least one of the next five years is 48% and is increasing with time. However, there is only a small probability (10%) that the five-year mean will exceed this threshold. The Paris Agreement level of 1.5 °C refers to long-term warming, but individual years above 1.5 °C are expected to occur with increasing regularity as global temperatures approach this long-term threshold.
There is a 93% probability that at least one year in the next five will be warmer than the warmest year on record, 2016, and that the mean temperature for 2022–2026 will be higher than that of the last five years
UN Environment Programme (UNEP)
Enhanced mitigation action is needed to prevent the goals of the Paris Agreement from slipping out of reach.
New national mitigation pledges for 2030 show some progress toward lowering greenhouse gas emissions, but are insufficient. The ambition of these new pledges would need to be four times higher to get on track to limit warming to 2 °C and seven times higher to get on track to 1.5 °C.
Global warming during the 21st century is estimated (with 66% probability) at 2.8 °C (range 2.3 °C–3.3 °C), assuming a continuation of current policies, or 2.5 °C (range 2.1 °C–3.0 °C) if new or updated pledges are fully implemented.
Collectively, countries are falling short of meeting their new or updated pledges with current policies.
Tipping Points in the Climate System
World Climate Research Programme /WMO
Further research on tipping points will be crucial to help society better understand the costs, benefits and potential limitations of climate mitigation and adaptation in the future.
The Atlantic Meridional Overturning Circulation (AMOC) is an important driver of the distribution of heat, salt and water in the climate system, both regionally and globally. Recent research suggests AMOC may be weaker in the current climate than at any other time in the last millennium.
The melting of the polar ice sheets on Greenland and Antarctica is also considered a major tipping point and would have global consequences due to substantial additional sea-level rise for hundreds to thousands of years.
Regional tipping points, such as the drying of the Amazon rainforest may have serious local consequences with cascading global impacts. Other examples include regional droughts which impact the global carbon cycle and disrupt major weather systems such as monsoons.
The combined effects of higher temperatures and humidity in some regions could reach dangerous levels in the next few decades, with physiological tipping points or thresholds beyond which outdoor human labor is no longer possible without technical assistance.
Climate Change and Cities
Urban Climate Change Research Network
Cities – home to 55% of the global population, or 4.2 billion people – are responsible for up to 70% of human-caused emissions while also highly vulnerable to the impacts of climate change such as increased heavy precipitation, accelerated sea-level rise, acute and chronic coastal flooding and extreme heat, among other key risks. These impacts exacerbate socioeconomic challenges and inequalities.
Globally, by the 2050s, over 1.6 billion people living in over 970 cities will be regularly exposed to 3-month average temperatures reaching at least 35 °C (95 °F).
Between March and May 2022, Delhi experienced five heat waves with record-breaking temperatures reaching up to 49.2 °C (120.5 °F). With half of Delhi’s population living in low-income settlements and highly vulnerable to extreme heat, this heatwave led to devastating socioeconomic and public health impacts. Low-lying coastal cities and settlements, such as Bangkok (Thailand), Houston (USA) and Venice (Italy), are highly likely to face more frequent and more extensive coastal flooding due to sea-level rise, storm surges and subsidence.
Cities have an important role in addressing climate change by implementing inclusive, urgent and scaled-up mitigation action and increasing the adaptive capacity of billions of urban inhabitants. Now is the time to integrate adaptation and mitigation, coupled with sustainable development, into the ever-dynamic urban environment.
Extreme Weather Events and Socioeconomic Impacts
WMO World Weather Research Programme (WWRP)
The number of weather, climate and water-related disasters has increased by a factor of five over the past 50 years, causing US$ 202 million in losses daily.
As attribution science continues to improve, evidence of the link between human-induced climate change and observed extremes, such as heatwaves, heavy precipitation and tropical cyclones, has strengthened.
Extreme weather events cause long-lasting socioeconomic impacts especially in the most vulnerable communities, which are often also the least equipped to respond, recover and adapt.
Successive tropical cyclones hit south-eastern Africa, causing devastation in Madagascar. The World Weather Attribution initiative found that climate change likely increased the intensity of the rainfall experienced due to these storms. As the atmosphere becomes warmer, it holds more water, which, on average, makes wet seasons and events wetter. With further emissions and rising temperatures, heavy rainfall episodes will become more common.
In June and July 2022, Europe was affected by two extreme heatwaves and drought. Portugal had a new July national temperature record of 47.0 °C, and for the first time on record, temperatures in the UK exceeded 40 °C. According to the World Weather Attribution initiative, human-caused climate change made the heatwave in the UK at least 10 times more likely.
Summer heatwaves pose a significant risk to human health, especially the elderly and infirm. Other factors – such as socioeconomic conditions, urbanization (the urban heat island) and levels of preparedness – can also increase vulnerability. First reports indicate that the heatwaves led to several thousand deaths.
Early warning systems: Adapting to climate change and reducing disaster risk
WMO/ UN Office for Disaster Risk Reduction
With 3.3 to 3.6 billion people living in contexts that are highly vulnerable to climate change, it is more important than ever for the international community to take ambitious action to not only mitigate emissions, but also adapt to climate change, particularly extreme weather and compounding events, which can lead to long-lasting socioeconomic impacts.
Early warning systems are effective adaptation measure that save lives, reduce losses and damages, and are cost-effective. Less than half of countries in the world have reported the existence of Multi-Hazard Early Warning Systems (MHEWS), with coverage particularly low in Africa, Least Developed Countries and Small Island Developing States.
A top international priority is to ensure that everyone on Earth is protected by MHEWS in the next five years. This will require collaboration across diverse actors and innovative financing solutions.
Posted on 2022-09-20 08:25