Why 2021 is the year to highlight how critical water sources are for the climate

This year, two momentous climate events will take place: the kick-off of the UN Decade for Ocean Science in June, and the United Nations Climate Change Conference (commonly known as COP26) in November.

This was not the intended timeframe. COP26 should have been held in November 2020, but was delayed due to the COVID-19 pandemic. However, the fact that these two events are now happening in this same year provides a unique opportunity.

This is the moment to remind ourselves how critical water sources are for climate. In fact, that water is climate.

As the UN suggests, water is the primary medium through which we will feel the effects of climate change. So, we need to make water protection is an intrinsic part of the global climate change strategy.

What do we mean when we say, 'water is climate'?

We live on a Blue Planet, with 70% of the surface covered by water. But, actually, less than 1% of the water is readily available for human use. The majority is found in saltwater (97%), ice or is underground (1%). These saltwater bodies play a vital role in regulating climate and weather, through absorbing solar radiation and releasing the heat needed to drive atmospheric circulation.

As Oceanographer Helen Czerski puts it, it is helpful to think of this process as the “Ocean Conveyor Belt”, because it is essentially the biggest engine on the planet, transporting heat from the equator to the poles. (Ocean temperatures range from about 0°C at the poles to about 30°C at the equator).

Why this is important is that this ocean cycle, which has existed for 4.5 billion years, enables the hydrological cycle (also known as the natural water cycle). When balanced, water evaporates from land and sea, condenses to clouds, then falls as precipitation. This cycle is critical to maintain rainfall patterns and replenish freshwater sources such as damns, rivers, glaciers and more.

This cycle also regulates the health of marine species like phytoplankton, kelp and seaweed, which produce up to 70% of Earth’s oxygen. These creatures draw down carbon dioxide alongside water and energy from the sun to make food for themselves, releasing oxygen in the process and supporting carbon sequestration.

Marine ecosystems also provide 3 billion people with their livelihoods, and affect the quality of the animals in the food chain that make their way onto our plates.

And finally, we depend on the ocean as the basis for creating over 95 million m3 per day. The process of desalination (literally de-salting) is used worldwide for drinking, agriculture and industrial needs, from the Middle East to Australia to California.

How is climate change affecting ocean ecosystems?

The effects of climate change are critically altering the ocean. As CO2 levels in the atmosphere rise (in April, atmospheric CO2 levels passed 420 ppm, an all-time high), the ocean tries to absorb more carbon. The oxygen content of the ocean has declined by around 2% since the 1950s and is expected to fall on average by 3-4% by 2100 overall due to climate change and increased nutrient discharges from fertilizers.

Additionally, the current best estimate is that 90% of all the extra heat energy from global warming has ended up in the ocean, resulting in thermal expansion. Combined with the accelerated melting of ice sheets, this is creating sea-level rises resulting in short-term destruction and long-term forced migration in low-lying countries. Some 630 million people live on land below projected annual flood levels for 2100.

In addition, this disrupts the natural water cycle, creating more erratic rainfall from floods to droughts, and long-term reducing the replenishment rates of glaciers, rivers and dams.

It could not be more critical to bring water to the forefront of the climate conversation.

What can be done

Imagine if, instead, policymakers used the UN Ocean Decade as the foundation on which to build the new commitments for COP26.

This would give new urgency to the need to, amongst other commitments:

Water creates climate, and our climate depends on protecting our water. We cannot tackle one without the other. Let’s hope that this opportunity is seized by the policymakers setting new global standards later this year.