IPCC report on the ocean and cryosphere

The document outlines the accelerating degradation of the Earth's cryosphere and oceans due to climate change. It details the rapid loss of ice sheets in Greenland and Antarctica, the thawing of permafrost, and the warming, acidification, and deoxygenation of the global oceans. These changes drive sea level rise, threaten biodiversity, and disrupt essential services like freshwater supply from mountain glaciers and food security from fisheries. The briefing emphasizes that while some damage is irreversible, cutting emissions can reduce risks and facilitate adaptation for vulnerable coastal and indigenous populations.

• The Arctic is warming significantly faster than the global average, with temperature rises more than double the global average over the last two decades. This has led to a dramatic decline in snow cover and a rapid decrease in sea ice extent and thickness, particularly in September, which declined by approximately 12.8 per cent per decade between 1979 and 2017.
• Ice loss from the Greenland and Antarctic ice sheets is accelerating and serves as the primary driver of global sea level rise. Between 2012 and 2016, Greenland lost roughly 247 gigatonnes of ice annually, contributing about 0.7mm to sea level rise each year.
• Permafrost thaw in the northern hemisphere is releasing carbon dioxide and methane, creating a feedback loop that amplifies warming. By 2100, between 30 per cent and nearly all near-surface permafrost could be lost if emissions are not reduced, potentially releasing hundreds of billions of tonnes of carbon.
• The global ocean has absorbed approximately 93% of the excess heat accumulated from climate change in recent decades and 20-30% of human-emitted carbon dioxide since the 1980s. This has resulted in warming, acidification, and a decline in oxygen levels, which have fallen by more than two per cent since the 1960s.
• Sea levels are projected to rise by 44cm to 74cm by 2100, depending on emission levels. This poses an existential threat to low-lying islands and coastal megacities, with annual global GDP losses from marine flooding estimated between 0.3 and 9.3 per cent by the end of the century.
• Mountain glaciers are receding rapidly, which initially increases water runoff (the 'peak water' effect) but eventually leads to shrinking water supplies. This threatens water security for regions such as the Central Andes and the Himalaya, and increases the risk of natural hazards like landslides and glacial lake outburst floods.
• Marine biodiversity is declining as species relocate polewards or into deeper waters to escape warming. Coral reefs are particularly vulnerable, with projected declines of up to 90 per cent even if warming is limited to 1.5 degrees, and near total loss at two degrees of warming.

APA

Team, Z. (2019). IPCC report on the ocean and cryosphere. Zero Carbon Analytics. https://zerocarbon-analytics.org/science/ipcc-report-on-the-ocean-and-cryosphere/

Chicago

Team, ZCA. IPCC report on the ocean and cryosphere. Zero Carbon Analytics, 2019. https://zerocarbon-analytics.org/science/ipcc-report-on-the-ocean-and-cryosphere/.

Wikipedia

{{cite report |last1=Team |first1=ZCA |title=IPCC report on the ocean and cryosphere |publisher=Zero Carbon Analytics |date=27 September 2019 |url=https://zerocarbon-analytics.org/science/ipcc-report-on-the-ocean-and-cryosphere/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{team2019ipcc, author = {Team, ZCA}, title = {{IPCC report on the ocean and cryosphere}}, institution = {Zero Carbon Analytics}, year = {2019}, month = sep, url = {https://zerocarbon-analytics.org/science/ipcc-report-on-the-ocean-and-cryosphere/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }