Climate researchers are focused on the Arctic in recent years as nowhere else on Earth is our rapidly changing climate so apparent than the Arctic.

One of the most shocking examples of our rapidly changing climate is the loss of Arctic sea ice. The sea ice in the Arctic shrinks and grows with the changing of the seasons, but recent years have shown a stunning decline in the amount of summer sea ice left at the end of summer.

According to NOAA, "In 2012, summer minimum sea ice extent was recorded at 3.41 million square kilometers: the lowest of the satellite era, and 18 percent lower than in 2007, when the previous record of 4.17 million square kilometers was recorded."

Since 1979, the Arctic sea ice minimum extent has shrunk by more than 50 percent. Arctic sea ice plays a critical role in helping to cool the earth as its white surface reflects much of the sun's energy back to space.

Since much of the Arctic is ocean, the lack of sea ice means now the darker colored open ocean is absorbing heat, much like a black car is sweltering hot when left in the summer sun, and is amplifying warming in the Arctic.

As the National Research Council says in a report released last month entitled Abrupt Impacts of Climate Change: Anticipating Surprises, "The change in sea ice is largely irreversible, and substantial cooling is required to reestablish the original sea ice cover."

Once we lose this sea ice, there's no going back.

The opening of the Arctic poses a threat to our national security. Lack of sea ice means our Arctic coastlines must be monitored and patrolled more closely for increased traffic using now opened shipping lanes and searching for more extractable resources.

In November, Defense Secretary Chuck Hagel unveiled the Department of Defense's first ever Arctic Strategy, saying "As climate change and the viability of new energy sources shape the global environment, these shifts will affect our strategic outlook going forward, especially in the Arctic."

Recently Russian President Vladimir Putin told his military leadership they should build up their forces in the Arctic as a priority.

Tensions will increase as countries bordering the Arctic including the U.S., Russia and Canada maneuver to claim natural resources that may be beneath International waters.

In a sad and ironic twist, last September the first ever bulk cargo ship passed through the fabled Northwest Passage. The Nordic Orion, a 225-meter vessel carried a load of coal from Vancouver, British Columbia, and headed for Finland; its cargo destined to be burned adding even more greenhouse gases to the atmosphere and speeding the Arctic's demise even quicker.

In our glee to claim new shipping lanes and undiscovered natural resources in an ice-free Arctic, no one seems to question why the Arctic is becoming ice-free or what the implications of this may be for life on this planet.

Arctic species such as the walrus, ringed-seal, and polar bear depend on sea ice for their survival. In 2008 the world caught a glimpse of what the future may hold for polar bears in the Arctic when a satellite-tracked female polar bear and her yearling cub spent 9 days straight swimming in the Beaufort Sea searching for sea ice to hunt on. After a 426 mile swim she finally found sea ice, but in the process lost her cub, likely drowned due to exhaustion, and 22% of her body weight. Many Arctic species are threatened with extinction as the Arctic warms, there is nowhere left for them to migrate to.

A growing amount of research is linking the loss of Arctic sea ice with changing weather patterns around the world. Jennifer Francis, a Research Professor at Rutgers University, recently published research showing the amount of warming seen in the Arctic is causing the jet stream to slow and take large meandering patterns. The contrast in temperature between the equator and the poles is what pushes the jet stream. A warming Arctic means less of a temperature contrast resulting in a weakened jet stream, the jet stream looks less like the rolling west to east waves you would typically see, and more like a slow, meandering river with more of a north-south pattern.  This is causing some of the same weather patterns to be "stuck" in place for extended periods of time, leading to extremes in weather. It's also causing warmer southern temperatures to be pulled further north than usual and frigid Arctic temperatures to be pulled further south than usual, exactly why the "polar vortex" wasn't in the Arctic last week where it's usually found.

The news fortunately is not all bad. We have time to act to limit the amount of warming we are causing by burning fossil fuels, but time is limited. This will require us to act on a global scale and the U.S. must take a lead role in reducing our emissions. Most economists agree, a revenue-neutral carbon tax is the most efficient way to do so and if done smartly, can push other countries to do the same. Last June, President Obama asked Congress to bring him a market-based approach to addressing climate change, a revenue-neutral carbon tax is a conservative, free-market solution to the climate crisis.

Jon Clark is the Mid-Atlantic regional coordinator for Citizens Climate Lobby.