The report is another piece of compelling evidence that our planet is warming faster than at any point in modern history. It’s the 28th version of the annual checkup for the planet and updates numerous global climate indicators such as polar ice, oceans and extreme weather events around the world.
The fact that 2017 was either the second- or third-hottest year, depending on the dataset used, does not come as a surprise. It follows a string of record hot years in 2014, 2015 and 2016 — and while 2017 did not provide a fourth consecutive record, it was the hottest non-El Niño year seen.
The global average carbon dioxide concentration was 405.0 parts per million (ppm), which is the highest ever recorded and also higher than at any point in the last 800,000 years, according to ice-core data.
Oceans heating, rising
The oceans are also heating up, with significant planet-altering consequences.
The global average sea surface temperatures were near a record high, just slightly below the record from 2016, and the last three years have seen the hottest on record.
Warm seas equal rising seas, and 2017 set a new record for global sea level — which has risen year over year for six consecutive years and 22 of the last 24 years. Global sea level is rising at an average rate of 1.2 inches (3.1 cm) per decade, and that rate has been even higher in the most recent decades as sea-level rise accelerates.
Unprecedented coral bleaching also occurred during 2017, according to the report, which was the most widespread and destructive ever observed with hundreds of miles of corals in the Atlantic, Indian and Pacific Ocean basins experiencing up to 95% mortality in the hardest-hit reefs.
Both poles see record low ice
Both the Arctic and the Antarctic saw record low levels of sea ice during 2017, as warmer air and sea surface temperatures continued the trend of thinning out the polar ice.
“Today’s abnormally warm Arctic air and sea surface surface temperatures have not been observed in the last 2,000 years,” the study said.
In March of 2017, at the end of the ice-growing season when the coverage of sea ice in the Arctic reached its maximum extent of the year, scientists found it was the smallest yearly maximum in the 37-year record.
As for land ice, the news continues to be grim, which is bad news for global sea levels as melting glaciers are a significant contributor to rising ocean levels.
Glaciers across the globe lost ice mass for the 38th consecutive year — with declines “remarkably consistent” across all regions of the planet according to the report. To put the amount of ice lost since 1980 into perspective, the report states that “the loss is equivalent to slicing 22 meters (more than 70 feet) off the top of the average glacier.”
Extreme storms and rainfall
“Climate is not experienced in annual averages,” the report states, even though that is how we most often monitor and gauge the changes in our planet’s climate variability — both natural and human-influenced.
“Humans experience climate change and variability most deeply in the form of impacts and extremes,” according to the report — and 2017 certainly had plenty of them.
Even though globally tropical cyclone (hurricanes, typhoons, tropical storms, etc.) numbers were about average in 2017, the North Atlantic basin had one of it’s busiest years on record with three standout hurricanes.
Notable, deadly floods hit every continent except Antarctica — with India floods claiming 800 lives, Venezuela experienced its most devastating flooding in more than a decade, and flooding of the Niger and Benue Rivers in Nigeria displaced more than 100,000 people.
Global fire activity was the lowest since at least 2003, but extreme droughts in a few key locations led to a number of devastating fire seasons globally.
Source : Nbcnewyork