Scientists in Sweden are studying the climate-cooling effects of spruce forests

Scientists are exploring whether coniferous trees might help to counter the effects of global warming.

Deep in Sweden’s spruce forests researchers from Lund University are studying the cooling qualities of organic compounds called terpenes, which are abundant in conifer resin and also give spruce, fir and pine trees their distinctive scent.

When released into the atmosphere, these tiny particles interact with moisture to help form clouds that reflect sunlight away from the planet’s surface.

Cooling power

Forests cover nearly 70% of Sweden and play a unique role in influencing climate. Trees both absorb harmful carbon dioxide from the atmosphere and emit reactive gases that form secondary organic aerosol particles (SOAs). It is the abundance of these airborne particles that help sunlight-blocking clouds to form.

Commercially managed conifers, which are widespread in Nordic nations, produce a high concentration of SOAs compared to many other tree types. The Swedish research aims to improve scientists’ understanding of how these particles affect the climate, and whether planting more forests might have a cooling effect.

Adam Kristensson, one of the scientists conducting the study told Reuters: “It depends on where the forest is growing and what type of forest it is. In the southern parts of the world the trees are better at counteracting global warming than far up in the north.”

While this may sound like good news for people living in the Southern Hemisphere, it’s important to note that many countries have suffered devastating deforestation.

For example, figures released by Brazil’s environment ministry show the highest rates of deforestation in the Amazon for a decade. Despite opposition from environmentalists, the South American country saw an estimated 7,900 square kilometres of rainforest destroyed between August 2017 and July 2018.

However, some of the forest lost during land clearance for agriculture, animal pasture and development is being replaced in other regions by commercial plantations that add tree canopy. Although a great deal of biodiversity disappears in the process, planting new trees helps to combat global warming.

Climate change poses one of the most serious threats to civilization. The World Economic Forum’s Global Risks Report 2019 ranks failure to mitigate climate change as the second greatest danger facing the world this year.

The UN Intergovernmental Panel on Climate Change's (IPCC) Special Report on Global Warming sets a 12-year time frame in which the world must act on global warming to stay within the Paris Agreement’s target of 1.5°C above pre-industrial levels.

Time is running out to act on climate change, but studying Swedish spruce forests may shed more light on the role of trees in limiting global temperature rises.