*This article was originally published by Fair Observer.
Arek Sinanian | On October 8, the Intergovernmental Panel on Climate Change (IPCC) presented to the world its special report on the “impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty.”
As an intergovernmental body, membership of the IPCC is open to all member countries of the United Nations and the World Meteorological Organization. Currently 195 countries are members of the IPCC. Governments participate in the review process and plenary sessions, where main decisions about the IPCC work program are taken and reports are accepted, adopted and approved.
This report is provided in the context of the Paris Climate Agreement, signed by 195 nations at the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change in December 2015. The accord included the aim of strengthening the global response to the threat of climate change by “holding the increase in the global average temperature to well below 2°C above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.”
The report is a distillation of 6,000 referenced peer-reviewed scientific documents, written by 91 authors and 133 contributing authors, all of them international experts in the many fields associated with climate change. So, basically, the IPCC report represents the best and latest knowledge the world currently has in the field of climate science. It is the latest of five previous assessment reports and associated reports, all dealing with the complex issues relating to greenhouse gas emissions, their impact on global warming and climate change, and what needs to be done to reduce the predicted impacts of climate change.
Here’s a tiny bit of what it says. First of all, human activity is estimated to have caused approximately 1.0°C of global warming above pre-industrial levels. We are already seeing the consequences of 1°C of global warming through more extreme weather, rising sea levels and diminishing Arctic sea ice, among other changes.
A number of climate change impacts could be avoided by limiting global warming to 1.5ºC compared to 2ºC, or more. For instance, by 2100, global sea level rise would be 10cm lower with global warming of 1.5°C compared with 2°C. The likelihood of an Arctic Ocean free of sea ice in summer would be once per century with global warming of 1.5°C, compared with at least once per decade with 2°C. Coral reefs would decline by 70-90% with global warming of 1.5°C, whereas virtually all (> 99%) would be lost with 2ºC. Unfortunately, it appears that we are heading toward a 2°C increase.
Further, there are significant differences in regional climate characteristics between present-day and global warming of 1.5°C, and between 1.5°C and 2°C. These differences include increases in: mean temperature in most land and ocean regions (high confidence); hot extremes in most inhabited regions (high confidence); heavy precipitation in several regions (medium confidence); and the probability of drought and precipitation deficits in some regions (medium confidence).
As you’d expect for any predictive modeling, climate change models are very complicated and necessarily involve a huge number of iterations of numerous variables. And there are uncertainties in every one of those variables. That’s because the changes in the Earth’s climate are not only dependent on greenhouse gas emissions, but also numerous natural factors and effects such as sun flares and volcanoes.
Then there are expectations of future technological advances, global consumption patterns, the global economy, population growth and so on. And the further we go into the future, the larger these uncertainties get. Imagine trying to predict any one of these variables into the next century. But if we are to try avert the potentially catastrophic impacts of climate change, then we must try to do the best we can to predict each one of these variables and use extremely complex modeling techniques to predict the likely future outcomes of our current trend in greenhouse gas emissions and their effects on our climate.
As explained in my book, A Climate for Denial, here’s a constant problem scientists face in communicating and reporting the modeling outcomes. Depending on the assumptions made about the future, the economy, greenhouse gas emissions, etc., there is significant variation on global warming impacts on the climate. Needless to say, the forecasts vary from the optimistic (low climate change) to the pessimistic (severe climate change) to the very pessimistic (catastrophic climate change). The difficulty is this: Which of the various scenarios do the scientists report on, and which do we depend on and react to? So they report it all, including their assumptions, and this makes it difficult for a 10-second news grab.
The real problem is that in normal risk assessment and management, priority is usually given to the worst-case scenario. Imagine if the airplane you are about to board assumed the best-case scenario and only attended to the most optimistic outcome of an event; after all, if the computer system on the aircraft failed, chances are the pilot would be able to still fly the craft to land safely. No, you would want, and demand, that the worst-case scenario was well and fully identified, processes put in place, and the risk minimized to zero. After all, your life and everyone else’s on the flight depends on absolutely minimal risk of a catastrophic event. That’s why on an aircraft there are duplicate and triplicate systems for contingencies and backup particularly for potential catastrophic scenarios.
Yet when scientists present the pessimistic results of their climate forecasts, they are labeled scaremongers or alarmists and are blamed for exaggerating their predictions. On the other hand, if the scientists present the best case or optimistic scenario, then the response often leans toward doing nothing because, after all, maybe the problem isn’t that great anyway.
So, what are our contingencies and backups for catastrophic climate change? None. The Paris Climate Agreement does not deal with the worst-case scenario and is nowhere near enough to avert the dire predictions, but it was at least an agreement. We all know how difficult it is to get global agreements on anything. Are we doomed? Maybe not — not if we actively accelerate our responses. The reality is that the longer we delay the actions we must take, the more difficult it becomes to avoid the doom and the human and economic costs of adapting to climate change.
*This article was originally published by Fair Observer.