NASA issued a report on March 18th that identifies a disturbing trend of decreasing perennial sea ice in the Arctic despite this year's colder weather and the expansion of new ice.
"the scientists said they believe that the increased area of sea ice this winter is due to recent weather conditions, while the decline in perennial ice reflects the longer-term warming climate trend and is a result of increased melting during summer and greater movement of the older ice out of the Arctic.
Perennial sea ice is the long-lived, year-round layer of ice that remains even when the surrounding short-lived seasonal sea ice melts away in summer to its minimum extent. It is this perennial sea ice, left over from the summer melt period, that has been rapidly declining from year to year, and that has gained the attention and research focus of scientists. According to NASA-processed microwave data, whereas perennial ice used to cover 50-60 percent of the Arctic, this year it covers less than 30 percent. Very old ice that remains in the Arctic for at least six years comprised over 20 percent of the Arctic area in the mid to late 1980s, but this winter it decreased to just six percent.
According to Walt Meier of the National Snow and Ice Data Center at the University of Colorado, Boulder, as ice ages it continues to grow and thicken, so that older ice is generally also thicker ice. This winter the ice cover is much thinner overall and thus in a more vulnerable state heading into the summer melt season."
Last year, Arctic sea ice loss during the summer melt season blew away all records since satellite measurements began in 1979.
These are data points. They describe conditions outside of seasonal norms.
Here is another data point analyzing increasing trends in sea level rise. There are two major influences on sea level rise: thermal expansion with warmer ocean temperatures (which National Geographic says has already raised ocean levels between 4-8 inches and melt water from ice sheets.
You do not have to subscribe to the theory of anthropogenic global climate change to recognize that change is occurring. What you do with that information depends on what you believe is the proper role of governments and individuals in changing behavior and whether anything that our species can do will mitigate the change that these data and countless other data points represent.