Climate change has not stopped for COVID19. Greenhouse gas concentrations in the atmosphere are at record levels and continue to increase. Emissions are heading in the direction of pre-pandemic levels following a temporary decline caused by the lockdown and economic slowdown. The world is set to see its warmest five years on record – in a trend which is likely to continue – and is not on track to meet agreed targets to keep global temperature increase well below 2 °C or at 1.5 °C above pre-industrial levels.
This is according to a new multi-agency report from leading science organizations, United in Science 2020. It highlights the increasing and irreversible impacts of climate change, which affects glaciers, oceans, nature, economies and human living conditions and is often felt through water-related hazards like drought or flooding. It also documents how COVID-19 has impeded our ability to monitor these changes through the global observing system.
The United in Science 2020 report, the second in a series, is coordinated by the World Meteorological Organization (WMO), with input from the Global Carbon Project, the Intergovernmental Panel on Climate Change, the Intergovernmental Oceanographic Commission of UNESCO, the UN Environment Programme and the UK Met Office. It presents the very latest scientific data and findings related to climate change to inform global policy and action.
“Greenhouse gas concentrations – which are already at their highest levels in 3 million years – have continued to rise. This report shows that whilst many aspects of our lives have been disrupted in 2020, climate change has continued unabated,” said WMO Secretary-General, Professor Petteri Taalas.
Greenhouse Gas Concentrations in the Atmosphere (World Meteorological Organization)
Atmospheric CO2 concentrations showed no signs of peaking and have continued to increase to new records.
Reductions in emissions of CO2 in 2020 will only slightly impact the rate of increase in the atmospheric concentrations, which are the result of past and current emissions, as well as the very long lifetime of CO2. Sustained reductions in emissions to net zero are necessary to stabilize climate change.
Global Fossil CO2emissions (Global Carbon Project)
CO2 emissions in 2020 will fall by an estimated 4% to 7% in 2020 due to COVID-19 confinement policies. The exact decline will depend on the continued trajectory of the pandemic and government responses to address it.
During peak lockdown in early April 2020, the daily global fossil CO2 emissions dropped by an unprecedented 17% compared to 2019. Even so, emissions were still equivalent to 2006 levels, highlighting both the steep growth over the past 15 years and the continued dependence on fossil sources for energy.
By early June 2020, global daily fossil CO2 emissions had mostly returned to within 5% (1%–8% range) below 2019 levels, which reached a new record of 36.7 Gigatonnes (Gt) last year, 2% higher than at the start of climate change negotiations in 1990.
Global methane emissions from human activities have continued to increase over the past decade.
Emissions Gap (UN Environment Programme)
The Emissions Gap Report 2019 showed that the cuts in global emissions required per year from 2020 to 2030 are close to 3% for a 2 °C target and more than 7% per year on average for the 1.5 °C goal of the Paris Agreement.
The Emissions Gap in 2030 is estimated at 12-15 Gigatonnes (Gt) CO2e to limit global warming to below 2 °C. For the 1.5 ° C goal, the gap is estimated at 29-32 Gt CO2e, roughly equivalent to the combined emissions of the six largest emitters.
It is still possible to bridge the emissions gap, but this will require urgent and concerted action by all countries and across all sectors. A substantial part of the short-term potential can be realized through scaling up existing, well-proven policies, for instance on renewables and energy efficiency, low carbon transportation means and a phase out of coal.
Looking beyond the 2030 timeframe, new technological solutions and gradual change in consumption patterns are needed at all levels.
State of Global Climate (WMO and UK’s Met Office)
The average global temperature for 2016–2020 is expected to be the warmest on record, about 1.1 °C above 1850-1900, a reference period for temperature change since pre-industrial times and 0.24°C warmer than the global average temperature for 2011-2015.
In the five-year period 2020–2024, the chance of at least one year exceeding 1.5 °C above pre-industrial levels is 24%, with a very small chance (3%) of the five-year mean exceeding this level. It is likely (~70% chance) that one or more months during the next five years will be at least 1.5 °C warmer than pre-industrial levels.
In every year between 2016 and 2020, Arctic sea ice extent has been below average. 2016–2019 recorded a greater glacier mass loss than all other past five-year periods since 1950. The rate of global mean sea-level rise increased between 2011–2015 and 2016–2020.
The Ocean and Cryosphere in a Changing Climate (Intergovernmental Panel on Climate Change)
Human-induced climate change is affecting life-sustaining systems, from the top of the mountains to the depths of the oceans, leading to accelerating sea-level rise, with cascading effects for ecosystems and human security.
Ice sheets and glaciers worldwide have lost mass. Between 1979 and 2018, Arctic sea-ice extent has decreased for all months of the year. Increasing wildfire and abrupt permafrost thaw, as well as changes in Arctic and mountain hydrology, have altered the frequency and intensity of ecosystem disturbances.
The global ocean has warmed unabated since 1970 and has taken up more than 90% of the excess heat in the climate system. Since 1993 the rate of ocean warming, and thus heat uptake has more than doubled. Marine heatwaves have doubled in frequency and have become longer-lasting, more intense and more extensive, resulting in large-scale coral bleaching events. The ocean has absorbed between 20% to 30% of total anthropogenic CO2 emissions since the 1980s causing further ocean acidification.
Global mean sea-level is rising, with acceleration in recent decades due to increasing rates of ice loss from the Greenland and Antarctic ice sheets, as well as continued glacier mass loss and ocean thermal expansion.
Climate and Water Resources (WMO)
Climate change impacts are most felt through changing hydrological conditions including changes in snow and ice dynamics.
By 2050, the number of people at risk of floods will increase from its current level of 1.2 billion to 1.6 billion. In the early to mid-2010s, 1.9 billion people, or 27% of the global population, lived in potential severely water-scarce areas. In 2050, this number will increase to 2.7 to 3.2 billion people.
As of 2019, 12% of the world population drinks water from unimproved and unsafe sources. More than 30% of the world population, or 2.4 billion people, live without any form of sanitation.
The cryosphere is an important source of freshwater in mountains and their downstream regions. There is high confidence that annual runoff from glaciers will reach peak globally at the latest by the end of the 21st century. After that, glacier runoff is projected to decline globally with implications for water storage.
Earth System Observations during COVID-19 (Intergovernmental Oceanographic Commission of UNESCO and WMO)
The COVID-19 pandemic has produced significant impacts on the global observing systems, which in turn have affected the quality of forecasts and other weather, climate and ocean-related services.
The reduction of aircraft-based observations by an average of 75% to 80% in March and April degraded the forecast skills of weather models. Since June, there has been only a slight recovery.
In March 2020, nearly all oceanographic research vessels were recalled to home ports. Commercial ships have been unable to contribute vital ocean and weather observations, and ocean buoys and other systems could not be maintained.
The impacts on climate change monitoring are long-term. They are likely to prevent or restrict measurement campaigns for the mass balance of glaciers or the thickness of permafrost, usually conducted at the end of the thawing period. The overall disruption of observations will introduce gaps in the historical time series of Essential Climate Variables needed to monitor climate variability and change and associated impacts.