Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

New? Register here
Forgot your password?

Latest Posts


SkS Analogy 19 - A table full of crystal and ideal temperature

Posted on 7 March 2019 by Evan, jg

Tag Line

A table stacked high with delicate crystal is beautiful to look at, but impossible to move without significant breakage.

Elevator Statement

Stack crystal plates, bowls, glasses, and figurines on top of each other on a table. Done by a skilled artist it is a pleasure to look at. But try to move this delicate work of art from one place to another. The faster you move it the more damage there will be. The more crystal that is placed on the table and the higher it is stacked, the more precarious it is to keep balanced, and the more breakage occurs if the table is moved.

If the table had been placed at a different location before stacking the crystal, it could have been filled with the same crystal and created a similar, beautiful masterpiece at a different location. But stacking the table full of crystal and then moving it to a new place causes significant breakage.

Table full of crystal
So it is when we populate Earth with 8 billion beautiful people, inhabiting all of the available habitable zones, and then alter the location of the habitable zones through rapid changes in temperature, precipitation, and storms. Increasing the average temperature of the earth is not so much the problem as is the rate at which we are changing the temperature. The faster we raise the temperature, the faster climate changes, the quicker that habitable zones move, and the less time there is to adapt (i.e., move from one habitable zone to another).

Some ask rhetorically what Earth’s ideal temperature is. This is like asking what a table’s ideal location is. Damage occurs to the crystal on a table not because it is or is not in the ideal location, but because the table is moved after it is fully loaded with delicate crystal.

To minimize breakage, a table stacked high with crystal must either be moved extremely slowly, or left in its current location.

Climate Science

The current climate is the one to which humans have adapted themselves for the past 7000 years. This period has been marked by unusual stability of global temperature and sea level (Hansen and Sato, 2011). The climate during which human civilization developed is not necessarily the “best” nor “ideal” climate for human civilization to flourish: it is simply the one nature handed us at the end of the last glacial cycle and the one on which we built our cities and ports, carved out agriculture, established protected forests ... We settled down from our early life as nomadic bands of people. We should not assume that this stability will endure arbitrary pressure from 8 billion people.

A few of the critical factors for civilization to flourish are

  • Stable sea level for international commerce to be driven by ocean-going vessels traveling from the shores of one country to the shores of another.
  • Severe weather limited in scope and duration so as not to disrupt too much of earth’s societies at one time. This allows the unaffected to offer assistance to the affected.
  • Stable temperature, hydrology, nutrients, and populations of pollinating insects for successful agriculture.

During 100,000-year glacial cycles global average temperature varies by 5°C and sea level varies by 120m. During the last 2000 years, up to the start of the industrial revolution sea level varied by less than 0.5m. In geological terms a variation of 0.5m is remarkably stable.

International commerce has benefited from stable sea level. Since the start of the Industrial Revolution Earth has warmed by 1°C. The goal of the 2015 Paris Accord is to keep warming to less than 2°C. Although there is much debate about the magnitude and speed of future sea level rise, because there is about 66m of sea-level rise locked up in the world's ice, and because we've built settlements right up to edge of the oceans, even a "modest" sea level rise of 1m by 2100 will cause enormous problems and require expensive adaptation. And sea level will continue to rise after 2100. What impact will this sea-level rise have on international commerce? We can build floating harbors, but adaptation to continuously rising seas will be expensive.

How many days of freezing weather, how many hail storms, or how many floods are required to kill a crop? Successful agriculture requires fairly benign conditions over an entire growing season, meaning the temperature must remain in a relatively narrow range, hydrology must remain in a stable range, and there must be pollinators. How will the changing climate affect the preconditions for successful agriculture?

In the best case, the loss of agricultural productivity in one zone will be offset by a corresponding increase in productivity in another zone. Even in this “best case” scenario, however, if national borders separate these offsetting zones, movement of people from one zone to another will likely imply significant social disturbance, and with it, human suffering. Few people or organizations freely give up their “gains” to offset the “losses” of others.

In the worst case, in addition to shifting zones of acceptable habitation and agriculture, we will suffer a net global decline in fertile agriculture zones, causing suffering beyond the confines of the locations where the redistribution is occurring. The Russian drought of 2010 caused Russia to ban grain exports. When such a ban occurs, as a minimum, countries depending on grain imports would likely see price increases and food shortages. But the effects could be much more severe as people struggle to feed themselves and their families.

Just as rapidly moving a table stacked with crystal will cause much damage, rapidly increasing temperature through greenhouse gas emissions will cause much damage to human civilization.

Hang on, “It’s going to be a bumpy ride.”1


1. Reference to statement made by talking head in the movie "Harry Potter and the prisoner of Azkaban."


James E. Hansen and Makiko Sato (2011), Earth's Climate History: Implications for Tomorrow, NASA Science Briefs.

1 0

Printable Version  |  Link to this page


Comments 1 to 13:

  1. I have been using this one alot lately;

    To understand why it is so cold and yet it is AGW that is largely responsable I have a little exercise I want you to perform. First take off your shoes and socks, then go stand right infront of your refregerator/freezer (asuming it is a top freezer) now open the freezer door all the way. Stand there for a while. As you stand there you will notice your toes getting cold while at the same time you will watch as the ice cream melts. This is a crude but basic concept of what is happening. Record cold, lots of snow and ice in middle America, and rain falling on Greenland melting the snow pack. Crazy right?

    0 0
  2. Nice one jef. Very clear, descriptive image of what's happening.

    Also, in case you missed it, here was our take on another explanation of crazy weather.

    0 0
  3. Happened to just read this: Rain is becoming more frequent in Greenland and accelerating the melting of its ice, a new study has found.

    0 0
  4. Jef, is it a fact that rain is becoming a problem in Greenland or is it a media beat-up?!!?

    0 0
  5. I like this analogy. Often, when fighting climate science deniers, one will be challenged with the question 'What is Earth's ideal temperature?'. This one is actually on one of those denier lists of hard-questions-to-shoot-down-warmists-with that they pass around the denialosphere. They do have their tricksy defence mechanisms if one just replies with the standard 'there isn't an ideal temperature, but the relatively stable temperature of the last 10,000 years is what enabled our civilisation to develop'. I usually say that of course there is no ideal temperature, but clearly there could be many 'bad' temperatures for civilisation and I then hit them with this follow up.

    When arguing in this area, one will also often get at the same time the 'CO2 levels were much higher in the past and so were planetary average temperatures' meme - there were no ice caps and life existed in much greater numbers from pole to pole so why are 'warmists' worried about the future?

    I usually agree with the first part - it's true that, for example, during the Carboniferous and 'dinosaur' periods, Earth was much warmer and CO2 was a lot higher and abundant life was everywhere. The second 'why worry' part though is where denialist thought goes seriously astray.
    Sure, if we carried on loading up the atmosphere and global average temperatures climbed high enough, Earth would eventually stabilise in a state which would probably be more conducive to abundant life but what deniers turn a blind eye to is the timescales involved. It would probably take millions of years to get from where we are now to the fertile, universally warm, planet many deniers assert that climate science and policies are denying us all. They ignore the massive disruption, and probable mass species extinctions, that would occur as the ecosystems tried to adapt to the new and continually changing conditions. The ordered table of crystal would be continually shaken and disrupted for aeons. It may be true that that denialist 'destination' may be 'better' than what we have today, but no-one in their right minds who understands how ecosystems react to long term changes would want to go on the enormously long and dangerous ride it would take to get from here to there.

    0 0
  6. I googled "Earth's ideal temperature"...

    "GISS data show global average temperatures in 2017 rose 1.62 degrees Fahrenheit (0.9 degrees Celsius) above the 1951-1980 mean. According to GISS, the global mean surface air temperature for that period was estimated to be 57 F (14 C). That would put the planet's average surface temperature in 2017 at 58.62 F (14.9 C)."

    0 0
  7. Nick@5 thanks for your interesting comments.

    "abundant life was everywhere"

    It would be interesting to ask skeptics/deniers if it was the same life everywhere, or just life everywhere? We have 8 billion of exactly the same species living on Earth. There are species for whom oxygen is poisonous, and those species are doing just fine in some zones that lack oxygen. There are extremophiles that do well in near boiling water. There can be abundant life everywhere, but that does not mean that it is the same species everywhere nor that humans would be able to live everywhere on Earth under those conditions.

    I know you know this Nick, but just pointing it out as an argument to use with deniers/skeptics.

    0 0
  8. While life might be "everywhere", the sea level would be about 265 feet higher so all land near the coastline would be underwater.  That includes a large fraction of world wide farmland.  Land in Siberia would no longer be frozen but it is not suitable for growing most crops.  

    I don't thik it is a good idea to permantly flood all major ports and prime farmland in trade for useless peat land.

    0 0
  9. The Dinosaurs might have done well in a nice sub tropical climate but they in turn were wiped out by climate change, either a rapid event from an asteroid impact, or volcanism, or more gradual climate change here.

    We have to try to figure out how adaptable humans are. Some people make the argument that human technological society and its structures are very complex and inherently "fragile". They have certainly never been tested by a massive event like climate change, or a thermonuclear war or asteroid impact.

    The GFC (global financial crash of 2008) started with a few problems with american banks and nearly bought the entire world down with it. This suggests fragility under even moderate financial stress and climate change will undoubtably bring financial stress. We better pray our physical systems are more resilient than this.

    We do seem to do a little better in helping countries who have famines. But neither is it a brilliant performance. We are also a world of nation states, and while we cooperate sometimes, there's great suspicion and adversity as well and I dont see this improving fast. This is not going to help to efficiently resolve climate problems. It could end up being every man for himself in some sort of dystopican future.

    It's these fragilities that bother me, and would cause our civilisation huge problems. Its not that we are weak or that primitivism is a preferable lifestyle, its the way fragilities relate to a changing climate. We are not like a hardy simple slowly adapting baceteria.

    Climate change will bring large refugee problems, coastal protection problems, problems with staple grain crops, etc that look like they will stress the system like nothing else. Maybe we will rise to the challenge, maybe not. It would obviously require huge costs and a level of cooperation that would be unprecedented. I'm not sure humans are smart enough, or altruistic enough.

    0 0
  10. Just pointing out that the simplistic denialist meme that asserts 'we can adapt because life has survived and thrived after much bigger changes in the far past' does not fly on any human timescale.

    0 0
  11. Nick@10 Couldn't agree more with your statement.

    When I see a bird visit our feeders, I wonder what their life is like. When we see a bird of a particular species return year after year it seems like they live a stable, sustainable life. But it is not the same bird we see. They die and are replaced by a bird that looks the same and life goes on for their species. We can wax poetic about the life of birds and how stable and resilient their species is, but what is life like for the average bird? I fear that the benefits of modern society have dulled our ability to identify with truly sustainable life and what a struggle it is to live in equilibrium with the natural world.

    0 0
  12. I don't think the problem is that humans will not survive climate change. They probably will. But civilization will not survive climate change. It's going to make WWII look like a cake walk.

    1 0
  13. Hank@12 completely agree. We are talking about the difference between thriving as a global civilization and survival of the species. Going from where we are today to possible futures will not be pleasant.

    1 0

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

The Consensus Project Website


(free to republish)

© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us