New research suggests that a slowdown in global warming doesn't mean climate change is ending.
Researchers at the University of Edinburgh found that these short-term pauses in warming are a natural blip in an otherwise long-term upwards trend, suggesting that a current hiatus in the world's year-on-year temperature increases -- which have stalled since 1998 -- is temporary.
"Human activity is causing the word to warm, and natural variability can cause this trend to slow down or speed up," Dr. Andrew Schurer, who led the study, said in a statement. "Our study backs scientific understanding that climate change can experience periods of hiatus, but the overall trend is towards a warmer planet."
For the study, researchers analyzed temperature data from 1782 to 2000, comparing them with computerised climate models for the same timescale. They were able to separate the influence on climate trends of man-made warming -- such as from greenhouse gas emissions -- and of natural influences in temperature - such as periods of intense sunlight or volcanic activity.
They found that random variations can cause short term interruptions to climate patterns in the form of a pause or surge in warming typically lasting up to a decade. Extreme natural forces, such as strong volcanic eruptions, were shown to disrupt climate trends for decades.
The research highlights the impact of volcanic eruptions on climate, when particles produced can reflect sunlight from Earth, causing long-lasting cooling. The eruption of Mount Tambora in Indonesia in 1815 was among the biggest in recent times, causing a so-called year without summer. Scientists estimate that, if it occurred today, it would cause a 20-year climate hiatus.
The findings are detailed in the journal Geophysical Research Letters.
