Antarctica is stunning not only in its immeasurable geographic scale and unprecedented wildlife but the litany of ‘big picture’ stories raising global awareness about climate change.

Just this past week a groundbreaking article appeared in the prestigious journal Nature where scientists reported that major ocean currents in Antarctica are beginning to slow and warm because of increased Antarctic meltwater. Deep Antarctic currents are a key component of the ‘Great Ocean Conveyer Belt’ that transports cold, abyssal Antarctic water into both the southern and northern hemispheres. Remarkably, changes in our climate in the United States are influenced by Antarctic currents that travel from the Southern Ocean up in to the Atlantic and Pacific oceans and the Gulf of Mexico. Currents from the Southern Ocean influence our atmospheric pressure, humidity, air temperatures and wind patterns. The potential impacts of a slowing and warming Antarctic current could be dramatic, even impeding the flow of the Gulf Stream and rendering Arctic conditions to northern Europe.

The warming of the deep Antarctic Circumpolar Current (ACC) has additional big picture impacts. Studies funded by the National Science Foundation have discovered that predatory king crabs, formerly held at bay by the icy cold temperature are now moving up the Antarctic Slope from deeper water. If king crabs reach the shelf waters of Antarctica, their impact on prey populations such as clams, snails and other shelled invertebrates could be catastrophic. Antarctic marine invertebrates that live on the shelf have never had to confront crushing predators. Accordingly, they are weakly shelled and vulnerable to being crushed and eaten. The rewriting of the seafloor ecology of the Antarctic shelf due to a pending king crab invasion would be yet another big picture impact – an outcome of climate change that could very well result in significant loss of biodiversity.

Another big picture implication of the anthropogenic warming of the ACC is its capacity to accelerate the melting of Antarctica’s sea-ice, ice shelves, and glaciers. One famous case in point is the Thwaites Glacier located in western Antarctica adjacent to the Amundsen Sea. Scientists were surprised to discover that this glacier is retreating at an unprecedented rate, the result largely of warming ocean currents passing under the tongue of the glacier. Measurements indicate that the Thwaites Glacier retreated 14 kilometers over just a two-decade period (1992-2011). Scientists are concerned because the Thwaites Glacier is a figurative ‘cork’ that slows the flow of the two to three-mile-thick western ice sheet into the sea. It is possible that the loss of the Thwaites Glacier could result in the collapse of the West Antarctic Ice Sheet, an event that would herald dramatic increases in global sea level rise.

While sea-ice losses and gains vary across different regions of Antarctica, scientists now predict that within a few decades the sea-ice along the rapidly warming WAP will disappear. One of the three brushtail penguin species that lives on the Western Antarctic Peninsula (WAP) that will surely suffer is the sea-ice dependent Adelie penguin. Colonies of Adelie penguins on islands near the U.S. Palmer Station on the central WAP declined by 90% since the mid-1970′s. According to penguin expert Dr. Bill Fraser, the Adelie penguins near Palmer Station are suffering from increases in humidity from warming temperatures that result in unseasonal, late snowfall events that bury and kill the eggs of the Adelie penguins. Additionally, the Adelie’s are losing the sea-ice along the WAP which serves as a platform to toboggan on their feathered bellies to reach the ice edge facilitate feeding on shrimp-like krill.

Antarctica has an abundance of game-changing, big picture, global, climate change stories to share. Fortunately, these ‘wake-up’ stories are not all predicated on bad news. For example, there is the recent discovery of 1.5 million Adelie penguins on the Danger Islands, located just east of the tip of the WAP where temperatures are still low. Might these islands remain a repository for Adelie penguins should humanity slow down its pace of warming the earth? We can only hope, or we can spring to action to address climate change with the wondrous technology already in hand. I encourage everyone to choose the latter this Earth Day.

Dr. James McClintock is Endowed University Professor of Polar and Marine Biology at UAB, and author of Lost Antarctica (MacMillan).