Friday, August 16, 2013

Four Hiroshima bombs a second: how we imagine climate change

Hiroshima bomb - from: Wikipedia image
Where does the excess heat go that is trapped in our atmosphere by greenhouse gases every day?

The title of this post is a hat-tip to David Holmes, Monash University, Australia, who recently published an article with that title at The Conversation, discussing that the daily excess heat absorbed by Earth equals the heat released by well over four Hiroshima bombs every seconds.

It's actually well over four Hiroshima bombs every second, given that there are 86,400 seconds in a day and based on James Hansen calculations (at a Feb 29, 2013, TED presentation) that the current imbalance of 0.6 watts/square meter (which does not include the energy already used to cause the current warming of 0.8°C) was equivalent to exploding 400,000 Hiroshima atomic bombs every day, 365 days per year.

As illustrated by the graph below, most of this excess heat is absorbed by oceans and ice. Some of the heat is consumed by the process of melting ice into water, but most heat ends up warming up the oceans.
Graph by Sceptical Science
An earlier post (September 2012, added underneath) described the study by Nuccitelli et al. that measures heat going into the oceans in Joules and, as discussed above, measuring excess heat in terms of heat released by nuclear bombs might give more meaning to what is going on.

Where does the extra heat go? 

Global warming is causing Earth to heat up. As shown on the image below, by Nuccitelli et al., most heat goes into the oceans. A substantial amount of heat also goes into the melting of ice.

Warming of water in the Arctic Ocean

Global warming is heating up the oceans big time. As the image below shows, the global ocean heat content has been rising for many years.

White arrows mark ice drift directions. Red arrows mark 
the transport path of warm Atlantic water entering the 
Arctic where it submerges under the cold, ice-covered 
surface layer. Robert Spielhagen (IFM-GEOMAR, Kiel)
The Arctic is affected in particular by the Thermohaline Circulation.

Water flowing into the Arctic Ocean from the Atlantic Ocean is about 2°C warmer today than it has been for at least 2,000 years, according to a study published in Science. The current of warm water lies 50 metres below the surface, and can reach 6°C in summer — warm compared to Arctic surface waters, which can be -2°C.

At the same time, cold water and sea ice are driven out of the Arctic Ocean, along the edges of Greenland. The net result is a marked increase in the temperature of the water in the Arctic Ocean, especially the top layer of the water which causes the sea ice to melt.

The Arctic radiates comparatively less heat into space

Furthermore, cold layers of air close to the surface of the Arctic Ocean make it difficult for infrared radiation to go out to space, according to a study published in Science. These layers do warm up, but warming of these layers is directed downwards, thus amplifying warming in the Arctic.

Surface air temperatures in the Arctic are rising rapidly

Anomalies for surface air temperatures are higher in the Arctic than anywhere else on Earth. The increase in temperature anomalies appears to be an exponential rise. This is caused not only by the above-described points, but also by feedback effects as further described below.

How much will temperatures rise?
In the above graph, rising temperatures are compared to the global average for the period 1951-1980, which is typically used as a base period by NASA in temperature change analysis. The background behind this is that the U.S. National Weather Service uses a three-decade period to define "normal" or average temperature. The NASA Goddard Institude for Space Studies (GISS) analysis of temperature anomalies began around 1980, so the most recent 30 years at the time was 1951-1980.

The study 'Climate Impact of Increasing Atmospheric Carbon Dioxide', by NASA scientists led by James Hansen, describes those early efforts and was published in Science back in 1981. The image below is from the paper, showing that much of the extra heat trapped by carbon dioxide released by people in the atmosphere ends up in oceans.

The paper discusses how many years it can take for oceans to warm up, and the role of feedbacks in that process. The paper notes that a surface albedo change over land areas of 5% (equivalent to a 1.5% global change), would affect global temperature by 1.3°C, adding that paleclimatic evidence suggests that surface warming at high latitudes will be two to five times the global mean warming, due to snow/ice albedo feedback and greater atmospheric stability, which magnifies the warming of near-surface layers.

Feedbacks further accelerate warming in the Arctic

Feedbacks are described in more detail in posts such as Diagram of Doom (image below) and Changes to Polar Vortex affect mile-deep ocean circulation patterns.

Diagram of Doom
One such feedback is albedo change — retreat of Arctic sea ice results in less sunlight being reflected back into space, as further discussed in Albedo Change in the Arctic. Loss of Arctic sea ice is effectively doubling mankind's contribution to global warming. Increased absorption of the sun's rays is the equivalent of about 20 years of additional CO2 being added by man, Professor Peter Wadhams said in a BBC article.

One of the most threatening feedbacks is release of methane that are held in the currently frozen seabed. As the seabed warms up, it starts to release methane in what can be rather abrupt ways. Due to methane's high global warming potential and low levels of hydroxyl in the Arctic, this threatens to further accelerate local warming and trigger further methane releases, in a vicious spiral of runaway global warming.

from: Methane Hydrates

This situation calls for comprehensive and effective action as discussed at the climateplan blog.


- Accelerated Warming in the Arctic 

- Arctic Ocean is turning red

- How much will temperatures rise?

- Methane Hydrates


  1. There is no time to debate climate change it is time we awaken to Truth of Nature and her functioning. Earth has a parallel and multiple world design. It struggles to maintain certain ratio of energy to matter, thus heat of the environment. Two basic forces, unwinding [Heating or Sun force] and winding [cooling - Earth force] governs it. When in one world the ratio favors heat/sun and unwinding. In the other the ratio favor's earth forces [cooling/winding]. With industrial era we have been exponentially adding heat to the system. With globalization we have intruded into the night cycle when she works to cool. The consequence is increase of both forces. This is manifesting as accelerated change, with sudden peaks in heat and cooling leading huge fire/wind bound destruction. This is simultaneously accompanied by flash floods/snows. The winding eventually leads to earthquakes and volcanic eruptions that can turn the core of earth inside out . We are seeing all this on earth, yet nations and intellectuals ruling us are failing to awaken. Knowing the "principle and design" on which earth functions can save the situation for the world - some media should bring it to the worlds notice -

  2. To keep Earth alive is going to take some doing. Ad placed here. And undoing..
    Well, Two lines of evidence support heat radiating out from core and effect. 1) That deep ocean is warming and 2) that likely deep melt of water ice, form of methane clathrate, under thick East Antarctic ice sheet = That both these indicate upward transition of heat from Earth's core toward lithosphere. Net total of heat may indeed be same or slightly up from continuing radioactive decay at depth since forcing of anthropogenic greenhouse emissions took off accelerating and the process to large degree may be in hysteresis or lag time till full expression, but if we could take accurate temp reading of core temp it's my contention temp dropped a bit from approx 7 thousand degrees C. Note, citation needed to recent finding that core was 7,000 C Not 6,000 C. This is non factor save to raise awareness of the huge temp differential between Earth's core and surface temp and that latent heat properties of water and the capacity of water to hold heat and resist change are vast..
    2C is temp flux where unacceptable risk of danger started according to last UN Framework Committee on Climate Change assessment.. The new one is due out in stages starting likely in Sept 13.. Wadams Ice Melt rate info will be included.
    I want to postulate rate of Heat transfer is one thing when considered form from below but is another when considering the heat trapping properties of increasing veil of greenhouse, particularly Methane at 30 to 47 kilometers forcing the Stratosphere's heat inversion main driver to increase exponentially. The cause and effect are interacting with small brain man..
    So perhaps the time to do something happened like a little longer ago than 09.
    That said. If it was decreed. That all activities of value were to help EARTH and the others, near all exploits counter to this had to halt and be replaced by whatever best served the cause. Formerly postulated to be accomplished by Act of God modification to world fiduciary basic unit so it can't externalize harms to the environment and the poor any longer.
    Then the approx 7 billion people alive today could be give to make change 2C.