Climate Studies Underscore Need for Dramatic and Immediate Action

(CN) – Two new studies issued Monday paint a grim picture of the effects of climate change on global ecology.

In this Nov. 28, 2018 photo, plumes of smoke rise from Europe’s largest lignite power plant in Belchatow, central Poland. After several years of little growth, global emissions of heat-trapping carbon dioxide surged in 2018 with the largest jump in seven years, discouraged scientists announced in December 2018. (AP Photo/Czarek Sokolowski)

A research team led by Tufts University adapted a popular computational climate change assessment model to better account for uncertainties in human activity and the atmosphere’s sensitivity to carbon dioxide levels. With the new model, researchers explored the consequences of different climate change futures with an eye to better informing policy decisions.

Using the new model, researchers integrated variables such as population growth, the economy, technological advancement and the climate’s sensitivity to greenhouse gases, all of which could all affect the predicted results of policies and laws designed to curb global warming. In a paper published Monday in the journal Nature Climate Change, the team identified scenarios which led to a more tolerable climate future by exploring a wide range of variation within each uncertainty – and there aren’t many such scenarios.

“The consequences of severe warming can be dire. Given this potential for poor outcomes, it can be dangerous to consider only a few expert elicited scenarios,” said Jonathan Lamontagne, assistant professor of civil and environmental engineering at Tufts University and lead author of the study. “Planners need robust frameworks that broadly explore the uncertainty space for unforeseen synergies and failure mechanisms.”

According to the analysis, meeting the target of holding warming to less than 3.6 degrees Fahrenheit by 2100 – which experts agree is necessary for survival – is exceptionally difficult. Even in a scenario where all nations switch to carbon-neutral energy production by 2030, a tolerable future requires pinning hopes on the atmosphere being able to tolerate the carbon emissions already there.

Even so, our immediate and aggressive embrace of carbon neutrality is our only hope, according to the study.

“Despite massive uncertainties in a multitude of sectors, human actions are still the driving factor in determining the long-term climate. Uncertainty is sometimes interpreted as an excuse for delaying action. Our research shows that uncertainty can be a solid reason to take immediate action,” said Lamontagne.

Another study also published Monday in Nature Climate Change looked at the effect of current carbon emission rates on oceans. The researchers found marine microorganisms particularly in the Southern Ocean may cease to exist by the end of the century due to acidification.

Dead staghorn coral. (Arc Centre of Excellence Coral Reef Studies)

Acidification occurs when oceans absorb atmospheric carbon dioxide created by burning fossil fuels. The carbon dioxide alters the water’s chemistry, lowering its pH. The more acidic waters have less available carbonate, which microorganisms like corals and pteropods use to construct their shells.

The study, led by then-Colorado University-Boulder undergraduate research assistant Gabriela Negrete-García, used data from the Community Earth System Model (CESM) to forecast ocean acidification under several CO2 emission assumption scenarios. At current carbon dioxide emission rates, the depth at which some shelled organisms can survive could shrink from an average of 1,000 meters now to just 83 meters by the year 2100 – a drastic reduction in viable habitat.

Moreover, the change may happen with terrifying rapidity. In some places, the reduction in habitable depth could happen in a single year, and the loss of microorganisms could lead to cascading changes across ocean ecosystems, including disruptions of vital global fisheries.

“In the future, a pocket of corrosive water will sit just below the surface, making life difficult for these communities of primarily surface-dwelling organisms,” said Nicole Lovenduski, corresponding author of the study and a professor in CU Boulder’s Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research.

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