There are any number of scientific organisations – and some 97% of climate scientists – who say that climate change is happening and that the greenhouse gases we humans pump out by burning fossil fuels are the problem.  For example NASA.

The basics

NASA says that for at least the 400,000 years before 1950 carbon dioxide levels in the atmosphere had not exceeded 280 parts per million (ppm) - but by 2016 those levels had passed 400 ppm and that “There is no question that increased levels of greenhouse gases must cause the Earth to warm in response”.

Then it looks at the impacts of the warming planet.

Sea level rises

“Global sea level rose about 17 cm (6.7 inches) in the last century. The rate in the last decade, however, is nearly double that of the last century”. “Sea level rise is caused primarily by two factors related to global warming: added water from melting land ice and the expansion of sea water as it warms”.

Global temperature rise

“All 3 major global surface temperature reconstructions show that the earth has warmed since 1880. Most of this warming has occurred since the 1970s, with the 20 warmest years having occurred since 1981 and with all 10 of the warmest years occurring in the past 12 years”.

Warming oceans

“The oceans have absorbed much of this increased heat, with the top 700 metres (about 2300 feet) of ocean showing warming of 0.302° F since 1969.”

Shrinking ice sheets

“The continent of Antarctica has been losing about 134 billion metric tons of ice per year since 2002, while the Greenland ice sheet has been losing an estimated 287 billion metric tons per year”.

Declining Arctic sea ice

“Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades. The minimum area of sea ice, measured in September each year, is declining at the rate of 13.4% per decade.”

Glacial retreat

“Glaciers are retreating almost everywhere around the world – including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.”

Decreased snow cover

“Satellite observations reveal that the amount of spring snow cover in the northern hemisphere has decreased over the past 50 years and that the snow is melting earlier.”

Ocean acidification

“Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent. This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.”

The Great Barrier Reef

All of the above gives plenty of reason to worry about our wonderful reef. The Great Barrier Reef Marine Park Authority identifies climate change as “one of the greatest threats to the long-term health of the Great Barrier Reef.”

As Sir David Attenborough said in closing his recent wonderful series on the reef and the dangers it faces: "Do we really care so little about the earth on which we live that we don't want to protect one of the world's greatest wonders from the consequences of our behaviour?”

Jim Main

Cootamundra