Since the 1980s the number of climate-related disasters has tripled from 222 in 1980, to over 700 in 2016 according to the National Geographic. Global warming is disrupting natural weather patterns by increasing global rates of evaporation. In locations where rainfall is uncommon, this has the effect of drying up water resources more quickly and increasing the severity of droughts. In locations where rain is common, this will dramatically increase the amount and severity of rainfall causing more flooding.
Additionally, the warming planet is increasing ocean surface temperatures and causing widespread bleaching on some of the world’s most iconic reefs, including our own Great Barrier Reef. In 2015 and 2016, the first ever consecutive bleaching events occurred on the reef, with approximately 22% of all coral killed off in a single hit. Hot water temperatures cause the relationship of tiny plants called zooxanthellae and the animal polyps they feed to break down and the polyps reject their plant partners abandoning the coral. If the hot water persists for more than a week, usually coral will die.
Scientists are essentially unanimous, over 97% of papers written on the subject, and over 98% of authors on the subject agree that global warming is caused by human emissions of carbon dioxide and other greenhouse gases.
Concentrations of Greenhouse Gases, like carbon dioxide, have been increasing for decade after decade, ever since the beginning of the industrial revolution when coal and other fossil fuels started to be burned at industrial rates. In fact, the last time the Earth sustained this much Carbon Dioxide in the atmosphere was three million years ago, when the planet was warm enough for much of its ice sheets to melt causing sea levels to rise to around 20m higher than today.
Global temperature trends have followed the trend of increasing carbon dioxide, within the last 5 years being the 5 hottest years on record across the globe, according to NASA. The average temperature across the globe is now almost 1-degree Celsius higher than the historical average. While this not may seem significant, it is disrupting the Earth’s climate system on a global scale.
But how do greenhouse gases like carbon dioxide affect the global temperature? The video above can explain the concept far better than I can.
So, given the issue is happening now, is on a global scale and appears to be getting worse, what are individuals, companies and countries doing to fix this?
In late 2015, the governments of 196 countries came together to negotiate and discuss how to slow down and even stop the progress of global warming. The governments agreed, after discussion with scientists, that countries would need to limit warming to a maximum of 2 degrees Celsius, and should aim to limit warming to 1.5 degrees. This would be done by reducing greenhouse gas emissions and sequestering carbon emissions.
Each country agreed to achieve a certain amount of emissions reduction in the following decades, with some countries setting ambitious goals, and others setting more modest goals.