Climate Change Predictions: It's Now or Never
Researchers continue to assess the overall condition of the planet, making new assertions and predictions about climate change. Keeping up with all of the information can be overwhelming, so we’ve compiled a list of some of the key findings brought to the forefront of the climate change conversation over the past 30 years.
The First Assessment Report published by the Intergovernmental Panel on Climate Change (established in 1988 and more commonly known as the IPCC) appeared in 1990. One aspect of the report addressed questions related to rising sea levels. The findings indicated the global-mean sea level had risen one to two millimeters per year during the previous 100 years due to glacial melting and estimated an 18 cm rise by 2030 and 44 cm increase by 2070.
The Second Assessment Report, published in 1996, determined the temperature of the Earth had increased by 0.3 to 0.6 °C since the late 19th century and that sea levels would increase by about 50 cm by 2100. The latter estimate was smaller than the 1990 predictions for sea level rise, a hopeful sign.
The predicted rise in sea levels in these reports have come to fruition. In 2019, National Oceanic and Atmospheric Administration (NOAA) reported oceans have risen as much as six to eight inches since 1993 in some parts of the world.
Published in 2001, the IPCC’s Third Assessment Report found greenhouse gases to be at the highest levels ever recorded during the 1990s. This contributed to what they identified as an “unusual” 20th century climate, characterized by “unnatural” - man made - forces driving temperatures up.
Greenhouse gases - water vapor, methane, nitrous oxide, and chlorofluorocarbons - result from both natural and human activities. Methane derives from landfills, mass agricultural cultivation, and livestock cultivation. Nitrous oxide comes from fertilizers, biomass burning, and fossil fuels, while chlorofluorocarbons are completely synthetic, seeping into the atmosphere and destroying the protective Ozone layer.
As greenhouse gas production continued to increase during during the early 21st century, concerns for how they were changing the climate became more acute. By 2014, when the IPCC issued its Fifth Assessment Report, climate change was characterized a more critical threat - one necessitating action.
Of chief concern were greenhouse gas emissions and their impact, especially in developing nations and vulnerable communities. The report - issued in three parts - outlined the physical science, impacts and adaptations, and how to mitigate climate change.
The Effects of Rising Temperatures
The IPCC’s fourth report, published in 2007, noted increasingly visible signs of climate change, albeit largely as a regional phenomenon. Temperatures across the planet continued to rise, prompting predictions for more serious, frequent, and severe climate events. In terms of science, the report estimated a global temperature increase between 1.4 and 1.7 °C to the end of the 21st century. Highly variable by region, this would lead to more hot and fewer cold temperature extremes across the planet.
Additional predictions involved massive changes in global atmospheric and water cycles, triggering extreme weather events. There were fewer than 20 extreme weather events in the United States during the 1980s. During the 1990s and 200s, however, extreme weather events jumped to 35 and 40, respectively. Similarly, hurricanes have increased in frequency and intensity over the past two decades in the North Atlantic and Indian Oceans. Between 1966 and 2009, there were an average of six hurricanes each year. From 2000 to 2013, however, that number rose to eight.
In the United States, heatwaves and droughts have increased significantly during the last decade. In 2014, the National Climate Assessment found heat waves have gone from lasting days to weeks, tripling in length in Texas and the Midwest in 2011 and 2012. Subsequent droughts have triggered widespread increases in agricultural failures, wildfires, and heat-related deaths.
Globally, the IPCC projected increased food insecurities and forest destruction around the world. In 2019, it was reported, “500 million people live in areas that experience desertification...People living in already degraded or desertified areas are increasingly negatively affected by climate change.”
Wildfires are yet another area of concern. Wildfire seasons have expanded around the world between 1979 and 2013, with the Western United States currently experiencing seasons more than three months longer than during previous decades. Longer wildfire seasons mean more acres burned. In 2012, more than nine million acres burned in the American west, a number that increased to 10 million the following year. Wildfires caused comparable destruction in 2015 and 2017 as well.
The most recent climate change report will come out in 2021 but the IPCC has been active in addressing the increasingly dire outlook. Previous reports called for temperature stabilization in the face of irreversibility with instructions to policy makers, industries, national institutions, and everyone in between.
In 2019, the IPCC issued new guidelines for monitoring greenhouse gas inventories alongside a special report on the impacts of global warming of 1.5 °C or above. The supplemental report from the IPCC in 2019 pointed out that the global temperature was on track to increase by 1.5°C above pre-industrial levels at some point between 2030 and 2052.
The impacts from this include higher mean temperatures in most land and ocean regions and extreme heat, droughts, and heavy precipitation in highly populated regions.
By 2100, the global mean sea level will rise 0.1 meters lower than would be caused by a 2°C temperature rise - an urgent call to keep the temperatures from getting still higher.
With the next climate change report on the horizon, the IPCC has offered a roadmap to what needs to be done. To combat increasing temperatures, the IPCC calls for more sustainable development, efforts to eliminate poverty, and cooperation among private and public sectors.
Thirty years since its first assessment, the IPCC has called on consumers, producers, voters, and policy makers to work together, making it clear that hat now is the time to act.