Why We Are Here – Details
HPAC urges that we follow the most recent science that says we must restore our climate back to within the natural variation of our old climate by mid-century, so that we can stabilize current Earth systems collapses that create untenable tipping collapse response, return the weather extremes back to their former rare occurrences, and eliminate warming-caused injustice and inequity. This time frame is labelled the “point of no return” in climate science and means that once this time has elapsed, degraded systems (activated tipping responses) cannot self-restore even of the thing that caused the degradation to begin (warming ) is removed. These are things that our current climate culture of further warming to 1.5 degrees C above normal (1.8 F) cannot do because a 1.5 C target only reduces future warming. It is current warming that is causing the shift of our climate beyond the evolution of the human species. We must therefor eliminate current warming by restoring our climate back to the natural variation of our old climate, also known as the evolutionary boundaries of our Earth systems. This amount of warming above normal is about 1 degrees C, equal to about 350 ppm CO2 in our atmosphere where we are above 420 ppm today.
One might ask, why is such a small amount of warming critical? There are two parts to this answer: One is that our world’s systems (land and ocean and ice-based, physical and biological,) evolved within a narrow temperature range. Change this range of temperature and the species and mechanisms in our systems collapse, so that new species and mechanisms tolerant of the new conditions can evolve a new system. This takes decades to centuries to accomplish and in the meantime, once our systems begin collapsing, as they started doing when our climate’s maximum average temperature rose above about 1 degree C, the collapses do not stop, with the result of loss of environmental services like weather our world’s engineers have designed our infrastructures for, precipitation our world’s plants have evolved with, and most importantly absorption of greenhouse gases in the carbon cycle that in our old climate created a stable climate where humans and the rest of our world could safely exist. The other reason is that warming over land is twice the global average, and it’s not the average temperature that killed anything; it’s the extremes. Extreme temperatures are increasing even more greatly than the average temperature. So a 1.5 degree C above normal average global temperature is 3 degrees C warming over land, or 5.4 degrees F, with extreme temperatures many times this at 10 to 15 degrees F warming above our old climate.
One might also ask why the Intergovernmental Panel on Climate Change (IPCC) continues to suggest further warming to 1.5 C is safe. IPCC is sa slow consensus science organization whose seven-year review process compounds normally slow science resulting in dated, that enhances understated consusens decision making because of many different kinds of reticence. (see slides 28-34 here) Our slow and understated climate culture is why HPAC was formed. Our scientists, engineers, policy and advocacy experts read the latest science when it is published and interpret our future in a much less understated way than IPCC.
Current warming is also influenced by increasing natural emissions feedback loops from degraded Earth systems because of prior decades of accumulated climate pollution; from forest fires, methane bursts, polar ice loss, permafrost thaw, Amazon and degradation in tropical, temperature and boreal forests, plus degradation of our ocean systems and biology including corals, plus diminished downwelling of ocean currents that bury carbon in the abyss, and more. These feedbacks are exacerbating warming at an exponential rate. So in addition to phasing out fossil fuels, we must also do two other things simultaneously: remove, or treat the accumulating climate pollution in our sky, and use engineered solutions to temporarily cool our climate while removal and net zero can be fully implemented. The Intergovernmental Panel on Climate Change (IPCC) says we must remove up to 1,250 gigatons of CO2 from our atmosphere by 2100, in addition to creating net zero emissions by mid-century, just to limit warming to an untenable 1.5 degrees C warming which again, cannot stop tipping collapses and nonlinearly increases both weather extremes and warming-caused inequity and injustice above today’s levels and, only allows natural feedback emissions from degraded and collapsing Earth systems to increase further, which will result in total feedback emissions dwarfing humankind’s.
There is good news in that, because we now must cool our climate back to normal by mid-century, this means we do not have to remove additional feedback emissions rom warming that could be as much as 1,000 to 2000 gigatons of CO2 by mid-century. The further bad news is that because so many Earth systems are now degraded, which climate science defines as activation of tipping responses, their contribution to greenhouse gas removal from our sky is limited and in fact has reversed in many situations and will reverse in many others unless we cool with emergency urgency.
Many things contribute to the demand for restoring our climate. Greenhouse gas emissions of course, but also planetary darkening from polar ice loss and arctic greening. In fact, darkening oceans from polar ice melt is causing the planet and oceans to warm at an exponential rate. A shocking illustration of this is at the poles, which are now warming four times faster than the rest of the planet. All of the above means that even if we were to achive net zero emissions this instant, the climate crisis would continue to worsen. So the demand to address climate pollution not only includes addressing the future emissions that cause warming, but treating the past climate pollution that remains in our sky that is responsible for all the mayhem.
Therefore, global warming targets must not remain singularly fixed on IPCC scenarios because these are dated and future IPCC reviews are too slow to make a difference at their current publishing pace. The world community’s ultimate goal must be to disrupt the apparent credibility of IPCC and insert a new reality based on the most recent science that restore a safe and healthy climate back to our normal temperature, not that allows further warming based on dated climate science. Temperatures must be brought down to below 1.0 degree C of warming to do this and only implementing all three aspects of climate pollution, mitigation will we be successful and avoid existential futures: direct emergency cooling with engineered solutions, treating already accumulated climate pollution in our sky with engineered solution and ensuring further non-climate caused degradation of our natural systems is avoided, and by creating a sustainable fossil fuels emissions culture to carry us into the next century safely.
For an in-depth learning experience on the current state of climate tipping collapses and their responses, and on why it is that our climate future is so understated via 11 understating biases of our climate culture, see an Introduction to Advanced Climate Change (download).
