Despite ongoing efforts by national governments to reduce the impact of global warming, climate experts warn that the Earth is set to experience some of the most dramatic environmental changes over the next few years, including widespread melting of polar ice sheets, superstorms and a significant increase in sea level enough to sink many of the world's coastal cities.
When retired NASA climate scientist James E. Hansen and colleagues first came out with their initial findings on climate change last year, they said that unless the current pace at which people burn fossil fuels changes as soon as possible, the world is bound to experience an abrupt climate shift.
They said that while efforts have been made to curb greenhouse gas emissions globally, they are not occurring fast enough to help the planet steer clear of potential environmental risks.
The study triggered a heated debate in the scientific community, with some arguing that Hansen and his team's findings should have undergone peer review first before they were released. They also contested the rate of sea level rise mentioned in the draft report.
Now that the final version of the climate study has been released, Hansen and his colleagues reaffirmed the primary conclusions outlined in the initial draft, which is likely to cause another debate in the coming days.
"We're in danger of handing young people a situation that's out of their control," Hansen said.
Scientists who agree with the paper's findings said the conclusions may help explain geological evidence that point to several occurrences in the Earth's history when it experienced abrupt and drastic changes in climate.
However, other experts continue to disagree with the study's assertions.
Climate scientist Michael E. Mann from Pennsylvania State University said that some of the points highlighted in Hansen's study conflict with what is generally known about climate change, so much so that they require a high standard of proof.
Some of the criticism toward the new climate study stem from Hansen's own reputation as the paper's publishing scientist and as a prominent political activist.
Aside from having been arrested at rallies in the past, Hansen also joined a youth group who filed suit against the U.S. government for what they claim to be its inability to prevent climate change.
Hansen argues that the perilous state the world is in right now has led him to take on the role of more than just a scientist and to send a clear message about the dangers of climate change.
This may have turned Hansen into an inspiration to advocates of climate change prevention, but it has also caused some colleagues to doubt whether his findings have been skewed to suit his political goals.
The new climate study focused on events that occurred some 120,000 years ago, when the Earth's global temperature reached a level that is considered to be slightly higher than what it is today. Researchers believe that during that time, much of the planet's polar ice melted, and the water level in oceans rose by as much as 20 to 30 feet.
Climate experts agree that the Earth is about to experience an equal, if not even greater, increase in sea level. However, many assume that it would take hundreds of years before such a drastic increase could happen.
Hansen and his colleagues argue that this event could occur at a much faster rate than what people assume. It could lead to significant changes in the world's environment, including an increase in global sea level by several feet over the next five decades. This would force many people living along coastal communities to seek refuge elsewhere.
The researchers believe this scenario could be triggered by the melting of the planet's ice sheets, which would cause a slow down or even the total collapse of ocean current systems that help mitigate heat on Earth.
This in turn would cause high temperatures to focus on deeper portions of the oceans, triggering a melting of ice sheets located below sea level.
The temperature difference between the Earth's poles and tropics would become great enough that it would create more powerful storms.
The paper asserts that superstorms occurred during the warming of the planet 120,000 years ago, but this is being contested by other experts.
The findings of the climate study are featured in the journal Atmospheric Chemistry and Physics.
Photo: Graeme Maclean | Flickr