Laatste IPCC rapport over Klimaatverandering

Laatste IPCC rapport over Klimaatverandering

Laatste IPCC rapport over Klimaatverandering

Er is veel geschreven en gezegd in de media, maar we willen de lezers van deze blog op de volgende link wijzen. Raadpleeg voor het rapport, de samenvatting, de volledige inhoud en andere informatie: https://www.ipcc.ch/report/ar6/wg1/#SPM . Opmerking: IPCC staat voor “The Intergovernmental Panel on Climate Change”.

De conclusies zijn zeer helder en voor een groot deel al bekend bij velen van ons die zich richten op klimaatveranderingen en vereiste acties. Enkele citaten van het IPCC zijn hieronder vermeld. Ook de moeite waard om te lezen en te bestuderen is de regionale informatie, die in detail kan worden bestudeerd in de nieuw ontwikkelde “Interactieve Atlas” van IPCC (https://interactive-atlas.ipcc.ch/).

In de media lezen we soms verschillende kritieken op het IPCC-rapport. Sommigen stellen dat de scenario’s te pessimistisch zijn, enz. We hebben hier maar één simpele reactie op: “Als de patiënt ziek is en de oorzaken niet 100% bekend zijn, moeten alle voorzorgsmaatregelen worden genomen om ervoor te zorgen dat de patiënt blijft leven en dat er geen onnodige risico’s worden genomen”. Wereldwijd worden de IPCC-rapporten als leidend beschouwd; ook omdat er internationale consensus moet zijn voordat ze worden gepubliceerd.

Het IPCC-rapport zal hopelijk later dit jaar het middelpunt vormen van de COP26 (UN Climate Change Conference) in Glasgow; voor details over de COP26 verwijzen we graag naar:  https://unfccc.int/process-and-meetings/conferences/glasgow-climate-change-conference .

Enkele citaten van IPCC, en ze zijn “cursief” gedrukt en in de Engelse taal gelaten, om de essentie van de verstrekte boodschap niet verloren te laten gaan:

  • “Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea level rise—are irreversible over hundreds to thousands of years.”
  • “However, strong and sustained reductions in emissions of carbon dioxide (CO2) and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize.”
  • Faster warming:
    • “The report provides new estimates of the chances of crossing the global warming level of 1.5°C in the next decades, and finds that unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach.”
    • “The report shows that emissions of greenhouse gases from human activities are responsible for approximately 1.1°C of warming since 1850-1900, and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming. This assessment is based on improved observational datasets to assess historical warming, as well progress in scientific understanding of the response of the climate system to human-caused greenhouse gas emissions.”
  •  Every region facing increasing changes:
    • “Many characteristics of climate change directly depend on the level of global warming, but what people experience is often very different to the global average. For example, warming over land is larger than the global average, and it is more than twice as high in the Arctic.”
    • “The report projects that in the coming decades climate changes will increase in all regions. For 1.5°C of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health, the report shows.”
    • “But it is not just about temperature. Climate change is bringing multiple different changes in different regions – which will all increase with further warming. These include changes to wetness and dryness, to winds, snow and ice, coastal areas and oceans. For example:
      • Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, as well as more intense drought in many regions. 
      • Climate change is affecting rainfall patterns. In high latitudes, precipitation is likely to increase, while it is projected to decrease over large parts of the subtropics. Changes to monsoon precipitation are expected, which will vary by region.
      • Coastal areas will see continued sea level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas and coastal erosion. Extreme sea level events that previously occurred once in 100 years could happen every year by the end of this century.
      • Further warming will amplify permafrost thawing, and the loss of seasonal snow cover, melting of glaciers and ice sheets, and loss of summer Arctic sea ice.
      • For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events and sea level rise in coastal cities.”
  • Human influence on the past and future climate:
    • “The report also shows that human actions still have the potential to determine the future course of climate. The evidence is clear that carbon dioxide (CO2) is the main driver of climate change, even as other greenhouse gases and air pollutants also affect the climate.”
    • “Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net zero CO2 emissions. Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate,” according to the IPCC report.