New analysis of centuries-old trees in South America has revealed a strong correlation between wildfires and periods of warming.

The history of Earth's climate features frequent fluctuations in global temperatures, including many periods of warming. In modern history, periods of warming have occurred more frequently -- interrupted by shorter and shorter periods of more and more moderate cooling.

By comparing evidence of wildfire scarring among tree rings with climate records, scientists can tease out the relationship between fire and climate change.

In the most recent study, researchers at Portland State University surveyed evidence of wildfire scarring among 1,767 trees spread across 97 South American sites, including trees from a range of ecosystems. The evidence revealed a strengthening relationship between periods of warming and wildfire frequency.

Scientists shared their findings this week in the journal PNAS.

The South American climate is heavily influenced by the climate oscillation known as the Southern Annular Mode. SAM brings warm, dry weather and westerly wind patterns. SAM has become increasingly active over the last century. As a result, South America has experienced an increase in wildfire activity.

The oldest trees surveyed as part of the study prove the pattern has held for several centuries.

"We found that wildfire activity over the centuries has been increasingly favored by the warm phases of SAM going back to 1665," PSU geography professor Andrés Holz said in a news release.

Holz and his colleagues say the impact of rising greenhouse gas concentrations in Earth's atmosphere will strengthen the connection between warm periods and wildfire activity in the 21st century.

Tweet

Brazil's opening of Amazon to mining sets off alarm
Rio De Janeiro (AFP) Aug 25, 2017
When most of the world talks about the riches of the Amazon they mean the unique rainforest and so-called lungs of the planet. But Brazilian President Michel Temer has given the nod to a more literal sense of riches - mineral extraction - leaving environmentalists and activists including Gisele Bundchen up in arms. Temer's decision issued Wednesday scrapped a national reserve in the no ... read more

Related Links
Forestry News - Global and Local News, Science and Application

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only