The U.S.'s National Oceanic and Atmospheric Administration has released its report on the state of the climate in 2015.

And it's not looking good. 

Among its key observations: An increase in air and sea surface temperatures, a decrease in sea ice, the shrinking of the Greenland ice sheet and the changing behavior of marine life.

Not only were Arctic temperatures well above average, some areas saw the highest temperatures since record-keeping began in 1900.

For the second straight year, the Arctic is warming faster than the rest of the planet — a finding that was recently affirmed by Environment Canada scientists.  

The warmer air and sea temperatures are melting ice that, in turn, expands oceans and causes sea levels to rise.

It presents not only a growing danger to human populations along coastlines but for animals in both the Pacific and Atlantic oceans as well, where populations have been thinning along with the ice sheets crucial for their survival. 

The NOAA has been issuing Arctic report cards for 10 years now — a key tool in understanding how changes in the Arctic are impacting ecosystems. 

Its chief scientist Rick Spinrad says it's time to start paying close attention.

"This year's report shows the importance of international collaboration on sustained, long-term observing programs that provide insights to inform decisions by citizens, policymakers, and industry."

Seventy scientists from 11 countries contributed to the annual peer-reviewed report.

Air and sea temperature increasing

The report says the average annual air temperature in the Arctic this past year was 1.3 C above average. Arctic Ocean temperatures also continued to increase. Mean sea-surface temperatures in ice-free regions in August 2015 were as high as eight degrees in some areas.

Arctic Ocean ice is reaching its maximum extent earlier in the year with record low coverage. The extent of coverage at its smallest point in the summer has been declining at a rate of 13.4 per cent per decade. 

The trend is likely to continue at an exponential rate. 

Now that much of the older, thicker ice on the surface has melted away in the past several decades, the exposed younger ice is more vulnerable to melting in the summer. Across the Arctic, snow cover over land has declined 18 per cent per decade since 1979. 

Feedback loops

Walrus Rafts

In this July 17, 2012, file photo, adult female walruses rest on an ice flow with young walruses in the Eastern Chukchi Sea, Alaska. (S.A. Sonsthagen/U.S. Geological Survey/AP)

The melting and retreat of sea ice during spring means more sunlight is reaching the upper layers of the ocean. It also means more photosynthesis and ultimately more algae growth — the base of the marine food chain.

However that's not necessarily positive.

Widespread and exceptional phytoplankton blooms were observed in 2015 in Arctic seas. Arctic vegetation, as indicated by the satellite record, has been increasing over the past two to three decades, but not during the last two to four years where green tundra has been declining for reasons as yet unknown.

One of the report's major studies deals with the changing habitat for walruses. Traditionally, these large mammals use sea ice for mating, birthing, finding food and shelter.

In recent years, large numbers of walrus have been forced to haul out on land in northwest Alaska. Aerial surveys have shown major overcrowding which has led to deadly stampedes and food shortages.