The Intergovernmental Panel on Climate Change, or IPCC, released the first installment of the Sixth Assessment Report in August that pointed towards a particular threat to Humboldt county, the disruption of ocean currents. Just off the Humboldt coast flows the California current, which brings cold water down from the North Pacific, and the Davidson current that brings warm water up from the south. The circulation of this sea water is not only the driving force behind Humboldt’s wetter weather and lower temperatures, but they also bring in zooplankton that fish and birds prey on.
Christine Cass, associate professor and chair of Humboldt State’s oceanography department, said the weakening of the California current will have an effect on the offshore salmon populations who rely on the larger and more calorie dense plankton brought down from the north over the smaller plankton coming up from the south.
“If we have weaker CA current circulation, we are likely to see fewer of those northern plankton. This can have important implications for plankton predators, including birds and fish,” Cass said. “For instance, young salmon tend to be more successful if they enter the ocean at a time when northern zooplankton are more abundant. When we have fewer northern plankton and more of the southern plankton, the young salmon tend to have lower survival rates. In sum, changing the intensity of the CA current will impact the local plankton present, and could also impact the success of plankton predators.”
The arctic regions that the northern cold water originates from is poised to get hotter faster than most other regions, meaning that the cold water coming south will be heating up much faster than anticipated. This will mean the salmon will have less nutrient rich food during their mating season. With higher amounts of CO2 entering the atmosphere, the sea’s ability to absorb it and absorb heat gets strained. If ocean waters reach their maximum level of captured CO2, they will begin bouncing more CO2 and heat from the sun back into the atmosphere, compounding the effects of climate change and causing its worse effects to begin faster.
According to the IPCC report in August, all of the projections for more unprecedented weather patterns hinge largely on human activity.
“The magnitude of feedback between climate change and the carbon cycle becomes larger but also more uncertain in high CO2 emissions scenarios,” the report said. “However, climate model projections show the uncertainties of atmospheric CO2 concentrations by 2100 are dominated by the difference between emissions scenarios.”
The most important factor in reducing climate change is reaching net zero emissions as soon as possible. CO2 and greenhouse gas emissions are the largest contributors to the increase in unpredictable weather patterns.
According to IPCC working Group One chair Panmao Zhai in the August 9th press release, the only effective way to tackle climate change is for world leaders to reduce CO2 emissions as quickly as possible.
“Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net zero CO2 emissions,” Zhai said. “Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate.”