More whales in the ocean means less carbon dioxide in the atmosphere, which means a healthier planet for all beings

Humans have always revered whales, and for very good reason. They’re intelligent, charismatic and play an important role in our ocean’s ecosystem. But did you know that these magnificent mammals are also a key to helping us reach new climate objectives and further mitigating climate change?

The history of whaling

Whaling grew into a global trade in the 16th century, but it was in the mid-20th century that the situation spun out of control. Anticipating a rise in the price of whale oil, hunters went after calves, hunted out of season and sailed into sanctuaries. This left population levels at less than a quarter of what they were before commercial whaling began.

Thankfully, in the 1980s, the International Whaling Committee (IWC) imposed a global moratorium on hunting whales and populations have been slowly recovering. As of 2018, Antarctica's blue whale numbers increased from 360 to 3,000.

Raising awareness and educating the world about the intelligence of whales and the complexity of their language helped to restore these Cetacean populations. And recently we’ve learned that their preservation benefits more than just the survival of their species and their ecosystems—whales are also an effective nature-based climate solution for the entire planet.

How whales sequester carbon

In 2017, Steven Lutz, director of Blue Climate Solutions, produced a report that addressed whales’ role in carbon sequestration. It’s important to know that the ocean itself has absorbed one-third of all carbon dioxide emitted by human activities and most of the 0.6 degrees Celsius global temperature increase experienced over the last 30 years. Whales play a part in increasing the ocean’s ability to absorb CO2, but they also store CO2 in their own bodies (known as blue carbon).

Due to their large size, whales can store carbon in their blubber, even after they die. Once they die and sink to the  bottom of the ocean, they take all of that carbon with them and trap it for centuries. A 2010 study found that eight types of baleen whales carry 30,000 tonnes of carbon to the bottom of the sea each year. That means if whale populations returned to pre-whaling years, the carbon sink would increase by 160,000 tonnes a year. Instead, due to whaling, we’ve released 110 million tonnes of carbon into the atmosphere over the past century.killer whalePhoto by Thomas Lipke on UnsplashWhales also increase the ocean ecosystems’ ability to store additional carbon. When they swim to the bottom of the ocean, they bring up essential nutrients to the surface where they are scarce. This, along with whales’ iron and nitrogen-rich excrements, boosts the growth of phytoplankton and other marine plants that generate energy through photosynthesis and, in the process, remove carbon from the atmosphere. Another study says that 12,000 sperm whales in the Southern Ocean help capture 200,000 tonnes of carbon per year by stimulating these creatures.

Phytoplankton are believed to play a fundamental role in the generation of at least 50 percent of all oxygen found in the atmosphere, while capturing 37 billion metric tonnes of CO2, which amounts to 40 percent of all CO2 produced. It’s shown that phytoplankton capture approximately four Amazon rainforests worth of CO2 each year, and that just a one percent increase in productivity caused by whale activity would have a significant effect on global carbon sequestration.

The continued risk for whales and ocean life

While whales can't fix all of our environmental problems, protecting them would still make a tremendous impact on climate change. Unfortunately, whales are also feeling the consequences of our warming planet and oceans.

The increase in noise pollution has disturbed their natural marine environment, as whales rely on sound as an important sensory signal. It’s how they gather information, communicate and sense their surroundings. These disruptions alone have affected their reproduction, natural behaviour, physiology and increased their risk of mortality. Along with human impact, changes in ocean temperatures have caused a decline in food and a loss of habitat through acidification and freshening of seawaters. Indirect climate stressors like chemical pollution and plastic ingestion and entanglement have also been a threat to their existence.

Nature inherently has all of the solutions to combat climate change, but ecosystems need to be protected and preserved in order for it to due its job. Advocating for whale protection starts by educating others on the importance of whales, supporting whale conservation efforts and making changes in our daily lives. This can mean anything from eliminating plastic usage, minding the chemicals we put in our water system and ensuring that we’re consuming fish from small, sustainable fisheries.

Additional source: How Do Whales Change Climate