Hot off the Press: The New IPCC Report

The latest science confirms the need for urgent action.

The IPCC issued the massive first volume of its new report on climate change on Monday. This volume focuses on climate science: how much will the world warm, and what will the impacts be?  The bottom line is that the evidence is becoming ever firmer that (a) humans are causing an unprecedented rate of climate change, (b) we are starting to foreclose our ability to achieve less dangerous outcomes, and (c) failure to act will impose tremendous costs for generations.

Here are some of the key takeaways:

  •  Humans can release about 10 years of current global emissions to have an even chance of limiting warming to 1.5 degrees Celsius (2.7 Fahrenheit) above preindustrial levels. But the possibility of remaining below that threshold  are undeniably slipping away.
  •  Each of the past four decades has been successively warmer than any that preceded it, dating to 1850.
  • “It is virtually certain that hot extremes (including heatwaves) have become more frequent and more intense across most land regions since the 1950s. . .  with high confidence that human-induced climate change is the main driver of these changes.”
  • “Some recent hot extremes observed over the past decade would have been extremely unlikely to occur without human influence on the climate system.”
  • “There will be an increasing occurrence of some extreme events unprecedented in the observational record with additional global warming, even at 1.5°C of global warming.

Now for a deeper dive. Like its predecessors, the volume is a massive synthesis of thousands of scientific studies. It does have a number of new features. There is greater emphasis on regional impacts and extreme events. As in previous reports, this one also uses “Representative Concentration Pathways” (RCPs) that show how the world will respond to different trajectories for emissions of greenhouse gases.

Most notably, the new report adds “Shared Socio-Pathways” (SSPs) that look at what we can expect to see if society were to take various paths in terms of nationalism and inequality, as well as different paths toward economic growth.  There are five of these SSPs:

  • SSP1 in which population growth is moderate and economic growth is focused on sustainability and equality,
  • SSP2 where current trends continue to hold.
  • SSP3, a world of surging nationalism and regional rivalry , with population growth low in developed countries and high in the developing world.
  • SSP4, a world of surging inequality.
  • SSP5, a world of fossil-fuel based economic growth, in which global population peaks and then declines later in this century.

So basically, a relatively optimistic socioeconomic scenario, a baseline scenario following current trends, and three flavors of pessimism. One key indicator is how many people live outside what the IPCC calls the “human climate niche” in different combinations of emissions trajectories and socioeconomic scenarios. Only 1% of people now live in places where the annual average temperature is above 84°F but that number could ramp up very quickly.

This chart shows the emissions trends under some of the key scenarios:

Here’s how that translates into temperature:

The SSP1-1.9 scenario would keep emissions under the 1.5 °C goal of the Paris agreement. The SSP2-4.5 scenario kicks over the 2 °C line during this century, as do all of the less optimistic scenarios. Remember that this would mean twice as much temperature change as we’ve already experienced.

There are a lot of uncertainties at this point, but the biggest one is within our own hands. Every 1000 gigatons of carbon translates into about 0.5 °C of warming. So here’s the key question: How much more carbon are we going to load into the atmosphere?

 

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Reader Comments

4 Replies to “Hot off the Press: The New IPCC Report”

  1. Actually, science has been confirming the need for urgent actions for decades, but not even the UN and IPCC have been making the case because the power of money has dominated even their forums.

    And the worst is that the public has been considered too “impure” to inform, educate and motivate us to demand actions from our leaders.

    And there still is no hope because current politics in Washington, anti-vax movements, inequalities and Us/Them hatreds have us living in an age of chaos.

    So there can be no expectancy of hope as long as our best and brightest continue to refuse to educate We The People around the world in time for us to adapt, if there is enough time left to save an acceptable quality of life for our newest and future generations.

    It’s time for Universities to make urgent actions happen because you really are our last resort.

  2. In the 2006 “Global Warning” special issue of CALIFORNIA MAGAZINE there is a cover story “Can We Adapt in Time?” where Robert Ornstein and Paul Ehrlich are quoted from their 1989 book, “New World New Mind”: “The human nervous system, well matched to a world in which small, sharp changes were important but large gradual changes were not, is inadequate… Our nervous system and our world are mismatched now… Although we are evolving, our mental machinery will not change biologically in time to help us solve our problems.”

    It is now 2021, and the question is, have we run out of time for Universities to make urgent actions happen?

  3. Hmmm, still no answer.

    OK, let me say this another way because my concluding question, in replies to some of your previous posts, “have we run out of time for Universities to make urgent actions happen?” must have an acceptable answer for the human race to survive.

    Again, in “New World, New Mind” Ornstein and Ehrlich explain that we are causing our own out of control climate change problems because “we have created a world where our basic mental functions are no longer suitable.”

    Also remember that preeminent historians Will and Ariel Durant concluded, after 40 years of research and documentation, that civilizations fail because political or intellectual leaders failed to meet the challenges of change. And our political leaders have failed for far too long to deal with global warming in time because of the power of money is their highest priority.

    And, as I have said many times before to you, academics (intellectuals)/Universities are our last resort because you have the most evolved mental machinery today, hopefully enough to save the human race in time.

    So to ask my question one more way, do our Universities, with the best and brightest evolved minds on the planet today, have academics/intellectuals who have evolved enough to solve the global warming problems we created, in time to guarantee an acceptable quality of life for our newest and future generations?

    If you continue to not answer, I shall now consider your answer to be “NO”!

  4. EPITAPH

    Now that we have an answer of “NO” we still do not have immediately implementable solutions, on top of outrageous social-political facts such as a political party in Washington and in too many states that is dedicated to overthrowing our Democracy, plus millions of anti-vax/mask/democracy citizens that are threatening the lives of innocent children.

    Today, our last resort has failed since our best and brightest in 2021 still have not found a way, after decades of destructive predictions about global warming, thus they continue to fail to protect the human race from climate changes that are now destroying our planet and acceptable quality of life 24/7/365.

    So, we are experiencing the end of the end while all we can do is watch! Too bad that higher education isn’t working out to our advantage because we keep causing problems we can’t keep from destroying us!

    This is not a good epitaph for the human race, especially because our institutional leaders have failed to meet the challenges of change, while we created sources of our destruction that we could not control mainly because of the power of money regardless of consequences.

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About Dan

Dan Farber has written and taught on environmental and constitutional law as well as about contracts, jurisprudence and legislation. Currently at Berkeley Law, he has al…

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