2017 second hottest year recorded

There were indications through last year that it was likely to be one of the warmest on record, and that has been confirmed. Climate change/global warming is a growing concern for the well being of Earth and potentially for the future of the human race, which has been rapidly overpopulating the planet.

Stuff:  2017 was Earth’s second hottest year on record

Last year was Earth’s second hottest on record, just behind 2016.

The Copernicus Climate Change Service, the first major international weather agency to report on conditions in 2017, said temperatures averaged 14.7 degrees Celsius at the Earth’s surface – 1.2C above pre-industrial times.

Sixteen of the 17 warmest years have all been this century.

2017 was the hottest non El Niño year, and the third warmest ever recorded.

Scientific American:  The Top 7 Climate Findings of 2017

As the potential effects of climate change are seen around the world – from starving polar bears to record-breaking storms – interest in climate science is soaring. Scientists are digging into the “how,” “why” and “what’s next” of global temperatures, melting ice, emission sources and sinks, changing weather patterns, and rising seas.

The last year has seen major breakthroughs and advancements in climate research. Here are some of the biggest findings reported by scientists in 2017.

Temperatures and carbon concentrations are breaking records

In January, both NOAA and NASA officially confirmed that 2016 was the hottest year ever recorded. It’s the third time in a row that record has been broken – 2015 and 2014 were both determined to be the hottest years ever observed.

Just two months later, in March, NOAA scientists announced that atmospheric carbon dioxide concentrations are climbing at a record pace for the second year in a row.

Record low sea ice in the Arctic and Antarctica

Early March is around the time when Arctic sea ice typically reaches its maximum extent. Turns out it was the lowest max extent ever recorded in 2017, reaching just 470,000 square miles. For comparison, the average extent between 1981 and 2010 was about 5.57 million square miles. It’s the third year in a row scientists have seen a record winter low in the Arctic.

Around the same time, scientists observed record low sea ice in the Antarctic.

Sea-level rise is on the upswing

Multiple studies this year suggested that sea-level rise is occurring faster, or may be more severe in the future, than previous estimates indicate. One of the more dire of these was just published last week in the journal Earth’s Future. It suggests that better accounting for some of the physical processes affecting ice loss in Antarctica could double the sea-level rise expected under severe climate change scenarios. Another paper, released in October, came to similar conclusions. It also assumes a severe future climate change trajectory, and it updated Antarctic ice sheet dynamics.

These are some of the grimmer portraits of the future published this year, and their most alarming predictions rely on high-emissions scenarios that are not necessarily guaranteed to occur. But even more tempered studies are suggesting that future sea-level rise could be worse than we thought.

Some have tried to play down the risks of climate change by claiming that CO2 emission and sea level rise predictions were too high – but as scientific knowledge increases it’s just as likely they could have been too low.

Speaking of ice, glaciers are calving like crazy

In July, one of the biggest icebergs ever recorded broke from Antarctica’s Larsen C ice shelf and began drifting out to sea.

Just a few months later, in September, Antarctica’s massive Pine Island Glacier – which already pours about 45 billion tons of ice each year into the ocean – calved an iceberg four times the size of Manhattan, or about 100 square miles.

These are some of the most remarkable glacier calving events recorded this year, but they’re hardly the only ones. The U.S. Coast Guard announced this month that the number of icebergs recorded in the North Atlantic this year is nearly double what it was in 2016 – more than 1,000 total observed.

Generally speaking, it’s natural for glaciers to lose large icebergs every now and then. But as both air and ocean temperatures rise, scientists are observing growing amounts of ice loss from both the Greenland and Antarctic ice sheets and increasing instability among glaciers that back up to the sea.

Earlier this year, NASA images revealed a large new ice crack in Greenland’s enormous Petermann Glacier, which has already lost several gigantic icebergs over the last seven years.

Major discoveries about carbon

Using satellite data, researchers found that tropical forests – until recently thought to be one of the world’s biggest carbon sinks – are actually a net carbon source. Due to deforestation and degradation, they’re emitting about 400 million metric tons of carbon into the air each year.

There’s still great uncertainty about many aspects of the Earth’s carbon cycle, particularly when it comes to natural sinks like forests or the ocean.

But scientists are getting better at closing the gap. For instance, a report issued earlier this year by scientists with the Joint Global Change Research Institute suggested that methane emissions from livestock may be 11 percent higher than previous estimates suggested – a value that could help explain an ongoing scientific mystery about why atmospheric methane concentrations seem to be on the rise.

That could have serious implications for New Zealand’s agriculture.

These disasters could not have occurred without warming

…this year marks the first time some of the papers concluded that an event could not have occurred – like, at all – in a world where global warming did not exist. The studies suggested that the record-breaking global temperatures in 2016, an extreme heat wave in Asia and a patch of unusually warm water in the Alaskan Gulf were only possible because of human-caused climate change.

Scientists say these are likely not the only events to occur strictly because of climate change. They’re just the first to be discovered.

Global emissions are on the rise – again

A November report from the Global Carbon Project found that carbon dioxide emissions are growing again after being flat for three years. The findings have dashed experts’ hopes that global emissions had possibly peaked for good.

The research projects that 2017 could see a 2 percent increase in the burning of fossil fuels, bringing this year’s human-caused emissions up to about 41 billion tons of carbon dioxide. The reason for the uptick lies largely with China, the report suggests, where increases in the consumption of coal, oil and natural gas have driven its 2017 emissions up by about 3.5 percent.

China has been reported as working hard on increasing renewable energy use – see How China is leading the renewable energy revolution – so this may turn around.

But there are a lot of other countries and factors involved, so warming and it’s effects, like sea level rise and increased number and intensity of storms, will be of ongoing concern.