The UN Climate Action Summit on 23 September 2019 boosted ambition and accelerated actions to implement the Paris Agreement on Climate Change. The event saw 77 countries commit to lowering greenhouse gas emissions to net zero by 2050, while 70 countries announced they would accelerate their national action plans by 2020. In closing the event, the UN Secretary-General António Guterres stated, “You have delivered a boost in momentum, cooperation and ambition. But we have a long way to go. We need more concrete plans, more ambition from more countries and businesses. Nature is angry. And we fool ourselves if we think we can fool nature. Because nature always strikes back. And around the world, nature is striking back with fury.”
Of the many activists who mobilized to support the call for climate action in New York and around the world, none was more clearly heard than Greta Thunberg, who drove home the urgency and the determination of today’s youth to hold government leaders to account.
The landmark United in Science report, coordinated by WMO, also informed decision-makers at the Climate Action Summit. The Science Advisory Group to the Summit called for this high-level synthesis report to assemble key scientific findings from major partner organizations including WMO, UN Environment, Global Carbon Project, the Intergovernmental Panel on Climate Change (IPCC), Future Earth, Earth League and the Global Framework for Climate Services. The report underlines the glaring – and growing – gap between agreed targets to tackle global warming and the actual reality.
The report was presented at a high-level side-event on 22 September, with interventions from Andrés Couve Correa, Minister of Science Technology and Innovation of Chile, Krista Mikkonen, Minister of the Environment and Climate Change of Finland, and the Science Advisory Group co-chairs Leena Srivastava (IIASA Deputy Director General for Science as of 15 November 2019) and WMO Secretary-General Petteri Taalas, who also presented WMO Statement on the State of the Climate 2015–2019.
“Science informs governments in their decision-making and commitments. I urge leaders to heed those facts, unite behind the science and take ambitious, urgent action to halt global heating and set a path towards a safer, more sustainable future for all,” said Secretary-General Guterres in a foreword to the report. Similar declarations were made by UN, government and business leaders and civil society and youth representatives throughout the Summit.
“The Report provides a unified assessment of the state of our Earth system under the increasing influence of anthropogenic climate change, of humanity’s response thus far and of the far-reaching changes that science projects for our global climate in the future. The scientific data and findings presented in the Report represent the very latest authoritative information on these topics,” state the Co-chairs of Science Advisory Group. “It highlights the urgent need for the development of concrete actions that halt the worst effects of climate change.”
United In Science includes:
- WMO report on The Global Climate in 2015–2019, provisional findings until July 2019. The period is the warmest five-year span on record. The global average temperature has increased by 1.1 °C since the pre-industrial period, and by 0.2 °C compared to 2011–2015. Sea-level rise has increased from 3.04 millimeters per year (mm/yr) in the period 1997–2006 to approximately 4 mm/yr from 2007–2016. Sea waters are more acidic – observations show an overall increase of 26% in ocean acidity since the beginning of the industrial era.
- WMO Global Atmosphere Watch (GAW) Greenhouse Gas Bulletin: Levels of the main long-lived greenhouse gases, carbon dioxide (CO₂), methane (CH₄)) and nitrous oxide (N₂O) have reached new highs. In 2018, global CO2 concentration was 407.8 parts per million (ppm), 2.2 ppm higher than 2017.
- Global Carbon Project, Global Carbon Budget: Carbon dioxide emissions grew 2% and reached a record high of 37 billion tonnes of CO₂ in 2018. There is still no sign of a peak in global emissions, even though they are growing slower than the global economy.
- UN Environment’s Emissions Gap Report 2018: Global emissions are not estimated to peak by 2030, let alone by 2020. Current climate policies and ambition levels Nationally Determined Contributions (NDCs) would lead to a global mean temperature rise between 2.9 °C and 3.4 °C by 2100 relative to pre-industrial levels.
- IPCC Special Reports released in 2018 and 2019: Including the Special Report on Global Warming of 1.5 °C and the Special Report on Climate Change and Land and the Special Report on the Ocean and Cryosphere in a Changing Climate, reviewed in the next article.
- Future Earth and Earth League Climate Insights: There is a growing recognition that climate impacts are hitting harder and sooner than climate assessments indicated even a decade ago. Growing climate impacts increase the risks of crossing critical tipping points. These refer to thresholds that, if crossed, lead to far-reaching, in some cases abrupt and/or irreversible changes.
- Global Framework for Climate Services: Climate and early warning information services should underpin decision-making on climate action for adaptation.
