by Frank Thomas
A Synopsis of Climate Change in Plain English
The planet is warming and human agency is causing it. The sun is not causing recent decadal climate changes as research reported in this article shows. We are in an unprecedented, human-made climate warming powered by an ongoing striking growth in population, industrialization, and fossil fuel use which started in the 19th century and continues today. Resultant heat-trapping greenhouse gas (GHG) emissions and C02 atmospheric concentrations have risen RAPIDLY to levels unseen in almost a million years. Atmospheric C02 and temperatures have gone up and down within a stable range of 170-280 ppm for over 800,000 years – in contrast to an unnaturally high 405 ppm today reached over only a few decades. The last time atmospheric C02 was at this level, humans didn’t exist! What’s now happening is setting the climate our grandchildren and their children will inherit.
Most scientists agree the earth is warming and has warmed nearly 1 degree Celsius in the last 100 years (most of which occurred in last 65 years), temporarily reaching shocking records of 1.4°C to 1.6°C recently. The planet's historical warming and cooling shows an average rate of change of about 1°C per thousand years. So current global warming is more than ten times faster than ever before.
James Hansen notes with deep concern the global 12-month running mean average temperature is now 1.3°C above 1880 - 1920 average – comparable to the last warm Eemian interglacial period 130,000 - 115,000 years ago when sea levels rose 6-9 meters higher than today. Hansen warns there’s added warming in the pipeline now – e.g., ultimate outgassing of ocean-stored C02 – from climate’s delayed response and inability to speedily scale down on fossil fuels, contributing to the inevitability of continued global temperature rises. Oceans store heat but take many decades to fully respond to atmospheric GHG concentrations, and this will continue to affect the climate during the next millennium. (“Global Temperature in 2016,” James Hansen, Makiko Sato et al. , 18 Jan. 2017; and “Young People’s Burden: Requirement of Negative C02 Emissions,” by Earth System Dynamics, 4 Oct. 2016).
It is well known that there are galatial periods or Ice Ages during which the Earth gets much colder and Arctic ice covers much lower latitudes. Then there are interglacial periods when the Earth is much warmer which is the kind of period we're in now. The current period is called the Holocene. Scientists have analyzed in depth the Eemian interglacial, looking for analogies to today’s Holocene intergalacial period. Eemian temperatures rose 5°C higher in high latitudes of Northern Hemisphere versus Arctic’s 3°C rise today. Global mean average temperature was 1°C higher, similar to today. Eemian’s high temperature in the Northern Hemisphere came with lower C02 concentrations of 250-300 ppm but a very high summer insolation (solar radiation energy reaching earth’s surface) that melted ice sheets fast, creating the 6-9 meter sea level rise.
The scientific insight gained from the last Eemian interglacial revolves around the central question: how was the Eemian so much warmer with lower C02 concentration levels and yet a large sea-ice and ice-sheet meltdown that produced a much higher sea level increase (and 40 meter ocean waves) than the current Holocene interglacial has shown to date?
For the Eemian there were a number of natural forcings occurring at the same time. Earth orbital forcings, related peak seasonal insolation and global warming with rising GHGs led to the big increase in Northern Hemisphere summer temperature.
Eemian’s peak seasonal insolation and earth warming in Northern Hemisphere were further strengthened by a perihelion occurring also in summer rather than the winter. A perihelion is when earth is closest to the sun. This now occurs in the winter when earth is farthest from the sun. Other feedbacks expanding the insolation effect were a huge loss of sun reflectivity from reduced snow and ice cover and from reforestation at high northern latitudes where trees absorb more sunlight than C02, causing a net earth warming effect. If Eemian’s many thousands of years of strong insolation and feedbacks had taken place in the last century with the far higher atmospheric C02 levels of recent decades, our current Earth temperatures, ice-sheet melt and sea levels would be trending even HIGHER now than what occurred during Eemian.
Today’s observed annual rate of increase in C02 concentrations (2.3 ppm in 2016) and related global warming is occurring shockingly FASTER than during Eemian. Luckily, insolation from orbital forcings is expected to be much LOWER than insolation earth received in the rather warm Eemian period. (Skeptical Science: “The Last Interglacial Part Two: Why Was It So Warm?” by Steve Brown, 6 July 2011; “The Last Interglacial Part Five: A Crystal Ball?” by Steve Brown, 17 Nov. 2011)
Upsetting Earth's Energy Balance and Natural Carbon Cycle
Direct observations and actual measurements show a warming-up of the lowest part of the atmosphere, the troposphere. At the same time, levels above the troposphere from the stratosphere up are cooling because less radiation is escaping into space. This reflects a distinct human fingerprint. Sun cycles don’t explain this troposphere-warming and stratosphere-cooling because sun radiation warms the atmosphere uniformly at all levels. There’s no evidence of broad long-term changes in sun’s output over the past century. So, global temperatures are rising while solar output remains the same.There must be something else going on.
Natural variability has always existed. But the earth doesn’t warm up (or cool) because it feels like it; the warming-up happens because something forces it to. Well-documented scientific evidence confirms that natural variable climate forcings fall short in explaining current earth warming. Earth’s energy imbalance from added heat being trapped in the troposphere can only be explained by including man-made radiative forces, namely GHG increases produced largely by fossil fuel burning and deforestation in tropical zones.
FIGURE 1 : Natural vs. Human-Induced Changes in Global Temperature
Source: Skeptical Science – “Human Fingerprints on Climate Change Rule Out Natural Cycles.”
In FIGURE 1, the black curve represents observed temperatures; the blue curve is a computer simulation that accounts for natural variations like changes in the sun’s brightness and volcanic eruptions; the red curve includes all the natural variations in the blue curve, but adds C02 human emissions and reflective sulfate aerosols. Note that after 1970 observed temperatures aren’t consistent with natural variations. The gap is the human-made warming effect.
Over geologic time, natural cycles of global cooling and warming are considered to be governed by Milankovitch cycles – caused by earth orbital and axial variations that alter the sun’s radiation to earth, especially a ‘perihelion’ solar radiation when sun and earth are at their closest point of contact. Thus, solar insolation increases, causing larger ice sheet melt downs.
These natural cycles and ‘feedbacks’ initiate climate changes into 100,000 year cold periods known as ‘glacials’ and 10,000 to 30,000 year warm periods known as ‘interglacials.’ The natural cycle is the time between cold periods and warm periods … like the stable Holocene interglacial we’ve been in for ±15,000 years and normally expected to last another ±5,000 before next glacial occurs. BUT, a new report out dramatically increases that number!
Given the HUGE C02 emissions and atmospheric concentration occurring in a record geological timescale, the Holocene is NOT a normal natural cycle. The threshold for a glacial depends not only on insolation (amount of solar radiation received by earth’s surface) but also on atmospheric C02 content. A consensus of scientists in an exhaustive report (“Interglacials of the Last 800,000 Years,” by Past Interglacials Working Group,” 5 March, 2016) predict the Holocene will NOT revert to a glacial period for another 50,000 years – when the next strong drop in northern hemisphere insolation occurs.
This stunning news assumes current high C02 concentration of 405 ppm and rising is TIMELY reduced and stabilized, ideally at 300 ppm, but no more than 350 ppm. All living species could hardly adjust to 1,000 more years at current GHG concentration level, let alone 50,000 more years! We need C02, but not so much of it coming so lightning FAST from a geological timescale perspective and for so many thousands of years!
How lucky we are today that the sun’s radiation is much dimmer than in Eemian and, according to scientists, will remain so for a very long time. BUT, even a modest Holocene solar insolation process combined with continuation of current high C02 concentrations is a planet-heating-up recipe for an unfathomable climate disaster in this century.
While the sun had a negligible impact the last century, Arctic ice sheets are still melting down quickly. We are seeing a marked reduction in record time in sea ice and ice sheet volume. Greenland and Antarctic waters are showing far warmer surface temperatures. As oceans rapidly accumulate heat and melting increases also intensifying the positive feedback process, not only are large C02 outgassings and Arctic deep water methane releases possible, but a potential collapse of polar ice sheets and a sea level rise of several meters similar to the Eemian (NOT, as James Hansen warns, the IPCC’s conservative one meter sea rise prediction) is possible by end of this century.
Something else is happening. Beginning in the industrial age and especially since 1950, humankind has become the central driving force behind a departure from the natural cycle toward an era of human-induced global warming. Simply stated, man-made forcing of HUGE amounts of GHGs into the atmosphere at a geologically phenomenal rate has taken the lead away from earth’s natural cycle forcing and balancing process that occurs over thousands of years.
The energy change that a climate forcing, like GHGs, introduces into the climate system is measured in Watts/m2. The consequence of such a forcing is then expressed in terms of the change in the average global mean temperature. Scientists have found that a doubling of global atmospheric C02 from pre-industrial levels of 280 ppm to 560 ppm would cause an added energy (heat) forcing of 4 W/m2 by 2050. While a SMALL number, such a forcing translates into a HUGE global average Earth temperature increase of 3°C to 4.5°C by 2050.
TABLE 1 shows that the atmosphere had already reached an ‘extra’ heat balance trapped forcing of 2.6W/m2 in 2007. As human-made atmospheric GHGs increase, more of sun’s energy absorbed by the Earth and reflected back as infrared (heat) radiation into the atmosphere is trapped in the atmosphere – increasing earth warming.
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TABLE 1: 2007 Energy In and Energy Out of Climate System - Averaged Over the Whole Earth (Expressed in Watts Per Square Meter, W/m2)
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All Human Energy Usage .025 W/m2
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Extra Heat Trapped in Atmosphere by GHGs 2.60 W/m2
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Energy Received From Sunlight 341 W/m2
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Energy Reflected into Space 101 W/m2
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Energy Absorbed by Earth from Sunlight 240 W/m2
Source: Video: “Climate Change: A Scientist’s Perspective,” by Ralph Cicerone, July 28, 2016) (NOTE: Energy absorbed by earth from sunlight is 10,000 times all human energy usage. This illustrates three realities: raw sun energy is Free, Infinite, Clean; of 240 W/m2 energy absorbed by earth, about 70 W/m2 is absorbed by the atmosphere and 170 W/m2 is absorbed by earth’s surface. _________________________________________________________________
To be in natural equilibrium, the net inflow of sun energy must equal the outflow. As noted, over last 800,000 years before arrival of large scale human, industrial and agricultural activity, the carbon system and C02 concentration have been in remarkable equilibrium. However, over last 120 years, something different has been fundamentally resetting our climate on a dangerous path.
The natural balance of the carbon cycle has been upset by accelerated burning of fossil fuels leading to a 45% increase in atmospheric C02 since pre-industrial era. This has drastically disturbed the natural balance of the carbon cycle. A titanic store of carbon unavailable to the carbon cycle for millions of years is being put back into the system in an awesomely short time frame that’s simply scary – bringing C02 concentrations out of equilibrium, creating an unnatural forcing of global temperatures, further warming the planet.
As noted, most of sun’s energy entering Earth’s atmosphere must ultimately be sent back into space in order to have a constant global average temperature. About 30% of the 340 W/m2 of solar radiation received by earth, or 100 W/m2, is reflected back into space, leaving a net energy ‘budget’ of 240 W/m2 of sunlight absorbed by earth that warms the atmosphere and surface. About 50% of this incoming energy, or 170 W/m2, is absorbed by earth’s surface (oceans and land) and the balance of 20% or 70 W/m2 is emitted as infrared radiation back into the atmosphere. Much of this infrared radiation cannot freely escape into space because of absorption in the atmosphere by C02 and water vapor. This process traps the infrared radiation between the ground and lower atmosphere. The net reduction in earth’s efficiency to lose heat causes an earth energy imbalance that in turn causes increased earth warming.
Anything perturbing the Energy In and Energy Out balance eventually leads to a higher or lower Earth temperature. Internal natural variability like volcanoes, El Nino and La Nina events move energy between the atmosphere and ocean causing short-term warming and cooling, not long-term climate change. Long-term climate changes come from changes in Earth’s energy balance. They require external forces like the heating effect of atmospheric GHGs, changes in sun’s heat output, albedo feedbacks or amount of sun energy reflected back into space. Ice-albedo feedback (or snow-albedo feedback) is a positive feedback climate process where a change in the area of snow-covered land, ice caps, glaciers or sea ice alters the albedo which is the proportion of light or heat that is reflected back into space. Snow and ice, for example, reflect a lot of sun’s energy into space.
Scientists find that all measures of what’s happening now – land temperatures, atmospheric temperatures, ocean heat, ice sheet melt, sea level – point to a Holocene interglacial warming-up for several thousands of years. The challenge is how to contain, survive, adjust to the next 100 years of high warming, let alone another 50,000 years of high warming induced by human activities. We are producing over 39 billion tons of C02 yearly, 80% of which remains in the atmosphere for a century and 20% for even longer plus highly toxic CH4 and N2O emissions that remain for centuries. So, even if C02 emissions are stopped, multi-century climate change has been created by the immense accumulated past, current and future greenhouse gas emissions.
Trends in C02 Emissions and Temperatures
Extensive analysis of air bubbles trapped in ancient ice sheets show that C02 atmospheric concentrations have remained within a 170 – 280 ppm range for the past 800,000 years. During this time, a number of ±100,000 year glacial cycles occurred with ±20,000 year warming interglacials coming in between. Often, coincidences of solar maximums and variations in earth’s orbit have first triggered temperature changes later amplified by C02, CH4, N2O emissions.
Scientists believe rising temperatures at the end of ancient glacials probably created positive feedbacks of outgassings of ocean-stored C02 built up over thousands of years. So too today, one might think – given the exceptionally fast warming up of oceans from huge C02 emissions absorbed and expected to continue for another 50,000 years – that substantial ocean C02 outgassings may well occur in this 21st century and onward. Sudden bursts of ocean C02 into the atmosphere much larger than human-made sources could be a future feedback that profoundly amplifies global greenhouse warming.
The consistently constant, stable atmospheric C02 concentrations of 170 – 280 ppm for glacials and interglacials over past 800,000 years compares to the extraordinarily FAST 45% increase in atmospheric C02 over a TINY 266 years from 280 ppm in 1750 to 405 ppm in 2016; 75% of that increase occurred even FASTER over a TINIER 56 years from 310 ppm in 1960 to 405 ppm in 2016. And these figures exclude highly toxic methane and nitrous oxide emissions. Welcome to the world of anthropogenic climate change!
Comparison of Ancient Climates to Where We Are Now
FIGURE 2: Global Temperature and Atmospheric C02 – Ancient Geologic Time
Source: Skeptical Science – “Do High Levels of C02 in the Past Contradict the Warming Effect of C02?”
In the late Ordovician, C02 levels peaked at 4000 ppm in a glaciation that lasted one million years with no runaway greenhouse induced warming. Does the rise and fall of C02 concentrations before temperature changes over thousands of years – like occurred in the Ordovician-Silurian period 500 million years ago as shown in FIGURE 2 – prove that C02 does not drive warming?
The answer is: NO. The late Ordovician C02 levels peaked at 4000 ppm with a glaciation that lasted one million years. BUT, sun activity was extremely low. With a much dimmer sun over a very long period, a much higher C02 level is necessary to stop the earth from freezing over. The Ordovician very low sun output created the natural necessity for the C02 ice meltdown threshold to be in the 3000 ppm range. This compares to an estimated 500 ppm C02 ice meltdown threshold for the far higher solar output today. When the sun is much less active for repetitive periods, the C02 ice-threshold is much higher. In ancient times, there were large planet ecological, geological and ocean differences. These differences also helped draw down the spectacular Ordovician 4000 ppm C02 level naturally over thousands of years.
The Pilocene 3 million years ago was the last time C02 concentration levels matched today’s level. They remained within a 365-410 ppm range for thousands of years. Arctic temperatures rose 11 to 16°C global temperatures 3 to 4°C. Sea levels were around 25 meters higher than current level.
The late Cretaceous period 100 million years ago was very warm and atmospheric C02 concentration was around 1000 ppm. New research shows that NO continental ice sheets were formed in this period . This has led one scientist to conclude that a doubling of pre-industrial C02 concentrations to over 580 ppm this century could increase earth surface temperatures 6°C, as opposed to 3.0-4.5°C conservatively predicted by the IPPC. BUT, the Cretaceous C02 and temperature buildups occurred over many thousands, if not millions, of years. So life, ocean chemistry, and atmosphere had many millennia to adjust to the high CO2 concentrations and temperatures of that period.
Very high C02 levels coming before temperature rises 100 to 500 million years ago doesn’t say much of anything about global warming today. Insufficient data makes comparisons difficult and a little pointless as the earth was essentially a different planet back then. What is more relevant is that, before the industrial revolution (1750) and up to 1900, C02 content in the atmosphere remained fairly steady at 280 ppm for 800,000 years. In 1960, it began to soar from 310 ppm to 405 ppm today in a mind-numbing, short geological time frame.
Never before have atmospheric C02 concentrations increased so much and at such a fast rate - leaving not enough time for many organisms to get adjusted or survive. Scientists have determined that a 'natural' C02 concentration change of 100 ppm takes 5000 to 20,000 years. This compares to the ‘split time-second’ of 56 years for our 'human-made' C02 concentration to increase 95 ppm.
Disturbance of Natural Balance of the Carbon Cycle
FIGURE 3: Evidence We’ve Already Exceeded Limits of Natural Variability
Source: Skeptical Science – “Human Fingerprints on Climate Change Rule Out Natural Cycles”
The natural balance of the carbon cycle has been fundamentally disturbed in record geological time. The rate at which human activities are adding C02 to the atmosphere is overwhelming much slower natural processes. The natural cycle adds and removes C02 to maintain an energy balance while humans add 'extra' C02 without removing enough. The translates into a sharp turn to higher earth temperatures from 2000 to 2100, as shown in FIGURE 3.
Concerning the last century, scientists have concluded that detailed patterns in temperature change CORRELATE with increased C02 emissions but correlate little with increased solar radiation. Changes in Earth’s orbit on sun radiation reaching Earth’s surface have been negligible. The overwhelming natural forcings by human-made increases in atmospheric C02 levels, especially since 1950, have been creating a greater capacity for earth warming through the 'greenhouse effect'. GHGs act as a blanket that holds heat onto the earth. Much of the sunlight radiation coming in gets trapped and doesn’t go out.
Up to a point, this is a very GOOD thing! Thanks to the ‘natural’ greenhouse effect, Earth is a comfortable place in which to live. Absent the right balance of C02 and water vapor gases, life would be unendurable on this planet. Without some warming to evaporate water from oceans and lakes, land wouldn’t get water. Warming produces fewer droughts and deserts and expands agricultural possibilities.
BUT, too much of a good thing can be bad. C02 entering the atmosphere over such an incredible short time and causing severe global warming, weather volatility and more damaging storminess is a BAD thing. As one scientist said, “That’s like piling on a bunch of blankets in the summer time.” That’s exactly what’s happened in past decades. There’s now 45% more C02 and 250% more methane in the atmosphere than in 1750 – built-up mostly since 1950. Result? Costly, severely destructive recurring droughts, floods, heat waves and fires have been erupting at a scale and frequency natural factors can’t explain.
We are now ±15,000 years into the Holocene interglacial that scientists are now saying likely has another 50,000 years to go. That’s even more reason why limiting life-menacing climate change over such an extensive period will require substantial, sustained reduction of (a) human-made annual C02 emissions to 20 billion tons by 2035, and to below 10 billion tons by 2050; (b) reduction in atmospheric C02 concentrations to 375 ppm by 2035 and to a maximum of 350 ppm by 2050 – the FASTER, the BETTER. This is to avoid a lock-in threshold and consequent horrendous loss of living species and devastation to sectors of civilization from insufferably enduring high global surface temperature increases of 3°C to 5°C.
Climate Impact From Near Exponential Population Growth
During past 800,000 years, there was little increase in C02, CH4 and N2O emissions. Since 1950, these gases have risen dramatically – forced by vast industrialization processes (e.g. China) in concert with a near exponential 5 billion population growth since 1950 to 7.5 billion today … rising to 9.5 billion in 2050. Since Year 1 AD, it took 1,800 years of human history to reach a world population of 1 billion by 1800; but a SHORT 150 years to reach 2.4 billion in 1950; a SHORTER 66 years to reach 7.5 billion today; and a MERE 36 years to reach 9.5 billion in 2050.
These titanic increases, especially after 1950, have impelled the burning of ever larger amounts of fossil fuels, turning long-buried carbon into human-made, heat-trapping greenhouse gases in an earth shattering record time. This dual-dynamic gets to the core of what’s tearing earth's climate away from a natural balance of energy entering and leaving earth. Our human magnification of climate warming and weather crises presents a survival menace to 21st century living species – on a scale, one could say, potentially matching the rare massive asteroid striking Earth or the not so rare bursting of a series of giant volcanoes that occurred in past planet extinctions.
Lag Effect Between C02 Emissions and Temperatures
Geological history shows that C02 increases LAG temperature increases almost 2/3 of the time in past ice ages and interglacial warmings. BUT, contrary to what climate skeptics claim, this does NOT mean there's NO correlation between C02 concentrations and rising earth temperatures. This does NOT mean that C02 could NOT have caused (or cannot be causing) warming in between an interglacial warming and a cooling period.
This is because today we know we are adding C02 into the atmosphere way beyond previous peak levels of 280 ppm over past 800,000 years … and at an incredible speed in terms of geological time frames. We know what the GHG radiative forcing effects are from laboratory spectroscopy. We know the changes to earth’s energy balance. We know GHGs are the dominant heat-trapping contributors to the Holocene interglacial warming cycle we are in at a time of weak orbital forcing.
Yes, C02 does not always start the warming after an ice age or a glacial, but it does act as an amplifier of a warming triggered by orbital cycles. This was confirmed in a 2012 paper by Shakun et al, "Clarify The C02-Temperature Lag,” Skeptical Science; and in a 1990 paper by Claude Lorius and co-authored by James Hansen “The Ice-Core Record - Climate Sensitivity and Future Greenhouse Warming” That is why scientists say GHGs can be seen as a biogeochemical feedback triggered first by natural forcings – e.g. slow but recurring earth orbital variations around the sun that alter distribution of solar energy to earth over thousands of years. In this regard, GHGs are now amplifying a warming that started at an early phase of our 20,000 year Holocene interglacial. GHGs have become the leading ‘direct forcing’ of warming in Holocene – a 20,000 year interglacial normally expected to last another 5,000 years or so. BUT, as noted earlier, scientists now say it’s a warm, pleasant interglacial that will very likely last another 50,000 years if global surface temperatures don’t soar and get fixed 3°C - 5°C higher this century.
The IPCC conservatively projects a future global warming increase of 3°C ± 1.5°C if atmospheric C02 doubles from its historical 1750 preindustrial level of 280 ppm to 560 ppm by 2050. Recent yearly atmospheric C02 rates of increase have risen to 2.3 ppm. If that rate remains constant next 36 years, there will indeed be a doubling of C02 concentration to 560 ppm in 2050. The planet will by then be facing a massive Arctic and Antarctic sea ice meltdown exceeding the Eemian. (San Diego Free Press – Part 2: “Conversion to Renewable Energy Is Going Too Slowly to Avoid Catastrophe,” December 9, 2014)
Earth GHG Warming and Amplifying Feedbacks
The Eemian warm climate led to a significant melting of Greenland and Antarctic sea and ice sheets, thereby significantly lowering the reflectivity of sunlight into space. Eemian’s very high Arctic temperatures cannot be explained entirely by increased summer insolation in Northern Hemisphere. Multiple feedbacks played a major role in amplifying already very high Eemian insolation warming. And they are also playing a major role in the Arctic now. For example, loss of ice at the poles makes the ocean surfaces less reflecting and a greater absorber of sun energy which in turn increases the rate of ice melt, which in turn creates more earth warming. Making matters worse is the fact that Arctic ice is thinner since it’s being formed mainly in a shorter winter rather than a longer season. Thinner ice means Arctic ice is now melting more quickly.
The Eemian climate change was driven mainly by orbital cycles that spurred increased solar insolation in combination with lower GHGs than today. The Holocene climate change has been and is being driven primarily by a RAPID expansion to much higher C02 concentrations combined, thank God, with a much weaker insolation warming scientists expect will endure for a long time.
Our earth today, like Eemian period, is being struck by a growing intensity and frequency of costly heavier rains and floods from added air moisture. This turbulent weather can change to long heat waves and costly droughts as California has had. Key feedbacks that amplify original climate temperatures, weather changes and ocean warming and get stronger as they continue are:
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Ice-albedo feedback: when loss of sea ice and permafrost reduce surface reflectivity of sunlight because it sees more dark leading to more solar absorption, more warming, more melting.
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Water vapor feedback: when rising temperatures increase water vapor into the atmosphere expanding the heat trapping greenhouse gas Earth warming effect; the much high water vapor produced from the open ocean than from sea ice ocean adds to the earth warming.
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Warm tropical waters feedback: when warm tropical waters flow north, significantly adding to melting of Arctic sea ice and stirring up ever more turbulent storms and weather changes.
These feedbacks explain in part why the Arctic has had the greatest amount of warming and ice melt in recent decades – enhanced by warmer Antarctic water surfaces circulating north and amplifying substantial melting of Arctic ice.
Summary
In ancient times atmospheric gases, ocean chemistry and life had millions of years to adjust to big variations in temperature and atmospheric C02 levels that took thousands of years to build up – versus today’s extremely high C02 level built up in a phenomenally short 120 year time frame. The huge difference now, and an essential theme of this paper, is that we are emitting prodigious quantities of C02 at a rate, some scientists say, FASTER than even the most destructive climate changes in our planet’s geological past. And we have another 5,000, more likely 50,000, years to go to enjoy the Holocene, if we don’t humanly overheat it, destroying possibilities for living species to adjust.
The human-influenced rapidly steep rise in C02 concentrations has caused an Earth energy imbalance that is forcing higher Earth temperatures. We are approaching Eemian’s global mean temperature rise and are moving closer to its very high temperatures in the Northern Hemisphere, leading to a vast sea ice loss and 6-9 meter sea level increase over today’s level.
That’s the Holocene end-reality being imposed on planet Earth now by human warming activities from an immense growing population, industrial and agricultural base. We are overstocking the atmosphere with extra radiative warming energy by rapidly expanding the atmospheric greenhouse gas buildup from massive fossil fuel usage – converting humankind’s next 100-year planet stay into an environmental struggle to survive. And so far, C02 capture & storage technology (or technology to remove C02 from the atmosphere & store it) is a long way off from ever being of any help in time. The policy focus must be on sharply reducing fossil fuel usage as expeditiously as possible.
The science is crystal clear. Over the next 34 years, annual C02 emissions must be reduced from a huge 39 billion tons to below 10 billion tons by 2050; current atmospheric C02 of 405 ppm must fall back to the 300-350 ppm range by 2050. Failure here will lock in an earth energy imbalance, rising earth temperatures, ocean warming, ice sheet and permafrost melting, and a high sea level rise for many millennia. How soon could such a point of no return be reached? Nobody knows for certain.
Lacking 100% scientific certainty, it’s time to behave cautiously and pro-actively on something ALL humans have a vested interest in. We must come together on strong policy measures and incentives to stabilize global GHG concentrations by drawing fossil fuels, especially coal, down to no more than 30% of total energy usage in 2050. The GAP between where we are heading now and where we must go is GIGANTIC. (See an energy demand and sustainable energy supply projection: San Diego Free Press – Part 4: “Conversion to Renewable Energy Is Going Too Slowly to Avoid a Catastrophe”).
America is world’s highest per capita C02 emitter, producing 16% of global C02 emissions vs. EU’s 9.5%. China’s with 1.3 billion people is now producing 28% of global C02 emissions, getting a stunning 68% of its energy from dirty coal. Not far behind is India’s 1.3 billion people and huge 58% dependency on coal. In 2015, China burned 66 quadrillion Btu of coal, the rest of the world 56 quadrillion. In 2035, China is forecast to burn 108 quadrillion Btu of coal, the rest of the world 61 quadrillion. (source: U.S. Energy Information Administration). These are startling reasons – ignoring the fact fossil fuels will be exhausted and economically impractical by 2075 – why nations like the U.S., China and India must transition swiftly to 70% renewable energy and energy efficiency by 2050.
The global human-induced climate change situation we are in is serious. It’s planetary environmental suicide to allow atmospheric C02 concentrations to double to 560 ppm by 2050 – in a warm Holocene that normally will last another 5,000 years or so … a number that has shot up ten-fold to 50,000 years based on a recent scientific study.
If global C02 concentrations are timely reduced and stabilized to low 300 ppm levels by 2050, humankind and Earth ecosystems will have remarkably better chances to mitigate, delay, even avoid the worst effects of global warming – enabling future generations to continue to enjoy a livable Holocene interglacial this century and far beyond.
Frank Thomas
The Netherlands
March 22, 2017
Frank's Bio:
I’m a Maine native and graduate of Bowdoin and Dartmouth colleges. For many years, I was an independent management consultant and interim-manager for international Dutch firms manufacturing dredgers, engaged in offshore oil/gas exploration and contracting. Later I worked as a language/writing/presentation trainer for Dutch firms like ING, DSM, Siemens, Royal Dutch Shell, and Dutch Ministries of Foreign and Economic Affairs and Justice in the Hague, and also as lecturer at the Hague University and NTI University in Leiden.
Recent years, my time has been devoted to research and writings on grave global environmental, economic, and social problems. A primary focus has been exposing the scientific facts of climate change. The evidence is clear we are in a long-term trend towards increasing human-caused earth warming and extreme global weather events of severe, costly floods, droughts, heat waves that go beyond the bounds of natural cyclical variability. We are in an unstable climate system where drastic changes in human-made greenhouse gases and mild solar radiation are forcing Earth’s climate away from a natural balance of energy entering and leaving Earth. The SPEED of this change is unheard of! Ever more energy is entering entire global system. Unbridled rising concentrations of heat-trapping greenhouse gases accumulating in the atmosphere are certain to intensify future global warming and turbulent weather volatility. Average earth temperatures are likely to rise 2 degrees Celsius by 2036 and 3.5-5 degrees Celsius by 2050 – UNLESS C02 atmospheric concentrations are swiftly reduced to 300 ppm-350 ppm levels to reverse Earth’s dangerous energy imbalance. The battle is to avoid an irreversible C02 concentration well above current 405 ppm level, greatly risking the lives of our children’s children and their children.
References
Dr. Ralph J. Ciceroni: Former President, National Academy of Sciences:
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“Climate Change” – Evidence and Causes,” by R. J. Ciceroni, National Academy of Sciences, The Royal Society
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You Tube–PEI: “Climate Change: A Scientist’s Perspective,” Dr. Ralph J. Ciceroni, 28 July 2016
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“Science, Climate Change, and Conversations with Ralph Ciceroni – Conversations with History,” 18 March 2016, by UC Climate Solutions
James Hansen:
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“Young People’s Burden: Requirement of Negative CO2 Emissions,” James Hansen et al., by Earth System Dynamics, 4 Oct. 2016 (http://csas.ei.columbia.edu/2016/10/04/young-peoples-burden/)
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“Global Temperature in 2016,” James Hansen, Makiko Sato et al., 18 Jan. 2017 (http://csas.ei.columbia.edu/2017/01/18/global-temperature-in-2016)
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“Ice Melt, Sea Rise and Superstorms: Evidence from Paleoclimate Data, Climate Modeling and Modern Observations That 2C Global Warming Could be Dangerous,” by James Hansen, Makiko Sato et al., by Atmospheric Chemistry and Physics. 22 March 2016 (www.atmos-chem-phys.net/16/3761/2016/acp-16-3761-2016-pdf)
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“Abbreviation of Ice Melt Paper,” by Web Team, 22 March 2016 (http://csas.ei.columbia.edu/2016/03/22/abbreviation-of-ice-melt-paper/)
Shakun et al:
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“Global Warming Preceded by Increasing Carbon Dioxide Concentrations During the Last Glaciation,” by Jeremy D. Shakun, Peter U. Clark, Feng He et al., 5 April 2012, Macmillan Publishers Limited - Vol. 484 - Nature
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“Shakun et al. Clarify the CO2 Temperature Lag,” 10 April 2012 (https://skepticalscience.com/shakun-co2-temperature.lag.html)
Skeptical Science:
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“Human Fingerprints on Climate Change Rule Out Natural Cycles as Primary Causal Factors,” Skeptical Science, updated July 2015 (https://www.skepticalscience.com/global-warming-natural-cycle.htm)
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“Do High Levels of CO2 in the Past Contradict the Warming Effect of CO2,” Skeptical Science, updated July 2015 (http://skepticalscience.com/co2-higher-in-past-htm)
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“What Does Climate Change Tell Us About Global Warming?”, Skeptical Science, updated July 2015 (http://skepticalscience.com/climate-change-little-ice-age-medieval-warm-period.htm)
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“The Last Interglacial-Part2: “Why Was It So Warm?”, by Steve Brown, Skeptical Science, 6 July 2011 (https://skepticalscience.com/LIG2-1906.html) ; “The Last Interglacial-Part 5: A Crystal Ball?”, by Steve Brown, Skeptical Science, 17 Nov.2011 (https://skepticalscience.com/LIG5-1110.html)
Other References:
14. “Interglacials of the Last 800,000 Years, by Past Interglacials Working Group,” 5 March 2016 (http://onlinelibrary.wiley.com/doi/10.1002/2015RG000482/full); “Characterizing Interglacial Periods Over The Past 800,000 Years,” Cody Sullivan, 2 March 2016 (https://eos.org/research-spotlights/characterizing-interglacial-periods-over-the-past-800,000-years)
15.“Earth Will Cross the Climate Danger Threshold by 2036,” Michael E. Mann, 11 April 2014 (http://www.scientificamerican.com/article/earth-will-cross-the-danger-threshold-by-2036)
16.“The Human Contribution,” Dr. Stephen H. Schneider, Prof. of Biological Sciences, Stanford University (http://www.scienceclarified.com/scitech/Global-Warming/The-Human-Contribution.htm)
17.“Why Does CO2 Get Most Attention When There Are So Many Other Heat-Trapping Gases?”, Union of Concerned Scientists (http://www.ucsusa.org/global_warming/science_and_impacts/scienceCO2-and-global-warming-faq.html#.WJRsx9ThA0M)
18.“How Do CO2 Levels Relate To Ice Ages and Sea Level,” Rob Monroe, 20 June 2014 (https://scripps.ucsd.edu/programs/keelingcurve/2014/06/20/how-do-co2-levels-relate-to-ice-ages-and-sea-level/)
19. “The Real Truth About Greenhouse Gases and Climate Change,” by Dr. George MacCracken, 21 Sept. 2011, Climate Science Watch. MacCracken presents an illuminating rebuttal of well-known ‘skeptic Princeton physicist Dr. Willian Happer’s views expressed in his paper, “The Truth About Greenhouse Gases: The Dubious Science of Climate Crusaders ,” (http://www.climatesciencewatch.org/2011/09/21/maccracken-v-happer-the-real-truth-about-greenhouse-gases-and-climate-change/
20. “Study: The Late Cretaceous Period Was Likely Ice-Free,” by University of Missouri-Columbia. (https://wattsupwiththat.com/2013/09/26/study-the-late-cretaceous-period-was-likely-ice-free/)
