The latest Intergovernmental Panel on Climate Change (IPCC) Special Report highlights the urgency of prioritizing timely, ambitious and coordinated action to address unprecedented and enduring changes in the ocean and cryosphere.
The Special Report on the Ocean and Cryosphere in a Changing Climate, approved by the 195 IPCC member governments, reveals the benefits of ambitious and effective adaptation for sustainable development and, conversely, the escalating costs and risks of delayed action.
The ocean and the cryosphere – the frozen parts of the planet – play a critical role for life on Earth. A total of 670 million people in high mountain regions and 680 million people in low-lying coastal zones depend directly on these systems. Four million people live permanently in the Arctic region, and small island developing states are home to 65 million people.
Global warming has already reached 1°C above the pre-industrial level, due to past and current greenhouse gas emissions. There is overwhelming evidence that this is resulting in profound consequences for ecosystems and people. The ocean is warmer, more acidic and less productive. Melting glaciers and ice sheets are causing sea level rise, and coastal extreme events are becoming more severe
The report provides new evidence for the benefits of limiting global warming to the lowest possible level – in line with the goal that governments set themselves in the 2015 Paris Agreement. Urgently reducing greenhouse gas emissions limits the scale of ocean and cryosphere changes. Ecosystems and the livelihoods that depend on them can be preserved.
“The open sea, the Arctic, the Antarctic and the high mountains may seem far away to many people,” said Hoesung Lee, Chair of the IPCC. “But we depend on them and are influenced by them directly and indirectly in many ways – for weather and climate, for food and water, for energy, trade, transport, recreation and tourism, for health and wellbeing, for culture and identity.”
Professor James Renwick, Victoria University of Wellington said over one billion people depended on glacier ice for their water supply, and those communities would be increasingly put at risk as the ice melts away.
“Tens of millions of people live in low-lying small island nations and millions more live very close to sea level. Unless we take urgent action to reduce greenhouse gas emissions, vast populations will be displaced by rising seas.
“Every 10cm of sea level rise triples the occurrence of coastal inundation. One metre of sea level rise would threaten cities and communities all over the world, including New Zealand. The economic costs would be measured in the tens of billions here in New Zealand, and in the trillions worldwide.”
Professor Christina Hulbe, School of Surveying, University of Otago said hanging over the technical details in the report were two broad messages.
“First, the climate change drumbeat isn’t in the distance, it’s here and it’s loud, and second, the processes and impacts are highly interconnected. This means a number of climate change consequences are locked in but it also means that some of the most serious outcomes can still be avoided and, no matter what, the time we have available to get ready for the inevitable changes depends on how hard we keep pushing the climate system.”
The urgency expressed in the report is reflected in the legacy documents released at the global health promotion conference in Rotorua last April. While each statement focuses on certain areas, they are primarily a call for action to secure planetary health and sustainable development now and for the sake of future generations.