Climate change is the single greatest threat facing our planet today. Thanks to excess carbon emissions that have been growing steadily since the mid-20th century, average temperatures continue to rise worldwide. This leads to feedback mechanisms, such as rising sea levels, extreme weather, drought, wildfires, and glacial melting. This includes the Arctic Ice Pack, the East Antarctic glacier, and the Greenland Ice Sheet (GrIS), which are rapidly melting and increasing global sea levels.
Worse than that, the disappearance of the world’s ice sheets means that Earth’s surface and oceans absorb more heat, driving global temperatures even further. According to a new NASA-supported study by an international team of Earth scientists and glaciologists, the Greenland Ice Sheet is melting at an accelerating rate, much faster than existing models predict. According to these findings, far more ice will be lost from Greenland during the 21st century, which means its contribution to sea-level rise will be significantly higher.
Recent climate research, published in the Nature Climate Change journal has confirmed that melting icecaps in Greenland will contribute a minimum of 27cm rise in ocean levels even if we collectively stop burning fossil fuels immediately. We have reached a “point of no return”. And what makes it worse is that this is the most conservative estimate, as it only factors the contribution made by the ice shelf in Greenland. Projections have also confirmed that overall planetary warming has exceeded the original estimates for global heating, and that we are in for a difficult millennium if drastic action isn’t taken immediately.
There are several ways we can measure the progress of human civilization. Population growth, the rise and fall of empires, our technological ability to reach for the stars. But one simple measure is to calculate the amount of energy humans use at any given time. As humanity has spread and advanced, our ability to harness energy is one of our most useful skills. If one assumes civilizations on other planets might possess similar skills, the energy consumption of a species is a good rough measure of its technological prowess. This is the idea behind the Kardashev Scale.
The global climate is warming, and Earth’s polar regions are feeling the effects. A new study of the South Orkney Islands shows that the region has warmed significantly since the 1950s. The rise in warming in the South Orkneys exceeds the overall global warming.
In 2014, the UN Intergovernmental Panel on Climate Change (IPCC) released its Fifth Assessment Report (AR5). As with previous reports, AR5 contained the latest findings of Climate Change experts from all relevant disciplines, as well as projections about the near future. In short, the AR5 and its predecessors were assessments of the impact anthropogenic Climate Change was having on the planet and how we could avoid worst-case scenarios.
On Aug. 9th, 2021, the IPCC released a report titled Climate Change 2021: the Physical Science Basis. Combining the latest advances in climate science and multiple lines of evidence, this first report paints a rather bleak picture of the remainder of the 21st century. At the same time, it presents a call to action and shows how mitigation strategies and reducing greenhouse gas emissions will ensure a better future for all.
According to multiple sources – which includes NASA, the NOAA, the Berkeley Earth research group, and the Met Office Hadley Centre (UK) – global temperatures over the past few years have been some of the hottest on record. This is the direct result of anthropogenic factors like overpopulation, urbanization, deforestation, and increased greenhouse gas emissions (like carbon dioxide and methane).
According to a recent press release from NASA, in terms of global temperatures, 2020 was the hottest year on record – effectively tying it with 2016 (the previous record-holder). The release includes a dramatic video that illustrates average temperature increases since 1880 and the ecological crises that have taken place just this past year. This is yet another warning of how human agency is impacting the very systems we depend upon for our continued survival.
NASA and the NOAA just announced that 2019 was the second hottest year on record. It barely edged out 2016, the previous warmest year. And both 2019 and 2016 are part of the global warming trend: the last five years have been the warmest five years on record. And the last decade was the warmest decade.
Jeff Kargel is a Senior Scientist at the Planetary Science Institute in Tucson, Arizona. He is a geologist, a glaciologist, and a planetary scientist. Climate change is a major thread, and that is what he is here today to talk about.