2 Degrees Celsius – An Inevitable Global Average Temperature Increase?

The Global Carbon Project’s recent analysis on current carbon dioxide emissions published in the latest issue of Nature Climate Change underscores the necessity for action in emission reduction. The commentary’s authors concluded that the rapid growth in fossil fuel emissions makes a global average temperature increase of 2 degrees Celsius (3.6 degrees Fahrenheit) inevitable. It is this 20 Celsius global average surface temperature limit that was agreed to during the 2009 United Nations Climate Change Conference in Copenhagen, Denmark. And it is the goal of the in-progress 18th annual United Nations climate-change summit in Doha to create a world treaty, which would be signed in 2015, to slow global green-house gas emissions so that global average surface does not rise by 20 Celsius.

The commentary conclusions put this goal in question. As the authors state in the abstract, “The latest carbon dioxide emissions continue to track the high end of emission scenarios, making it even less likely global warming will stay below 2 °C. A shift to a 2 °C pathway requires immediate significant and sustained global mitigation, with a probable reliance on net negative emissions in the longer term.”

The commentary’s abstract is found at Nature Climate Change – The challenge to keep global warming below 2 °C.

Polar Ice Melting Fast

A new study published in Science on 11/30/2012 shows that the Antarctic and Greenland ice sheets are losing more than three times as much ice each year as they were in the 1990s. The melting of ice, two thirds of which has occurred in Greenland, has raised sea levels by 11.1 millimeters since 1992.

ice melt
Source: ESA/NASA/Planetary Visions
Based on the Shepherd et.al. Science study, this image of Antarctica has a superimposed chart of changes in global sea level due to ice sheet melting since 1992. The background image shows thickening (blue) and thinning (red) of Antarctica’s ice sheets over the same period.

The study is the combined work of 47 researchers from 26 laboratories and was  supported by the European Space Agency and the National Aeronautics and Space Administration. As summarized in the abstract of the Science publication, “We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth’s polar ice sheets. We find that there is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise.”

The research was undertaken as part of the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE). Read more on the study: Science – A Reconciled Estimate of Ice-Sheet Mass Balance

Sea Levels Rising 60% Faster Than IPCC Projections

New research published yesterday, 11/28/2012, in IOP Publishing’s journal Environmental Research Letters, reports that sea levels are actually rising at a rate of 3.2 mm a year compared to the best estimate of 2 mm a year in the Intergovernmental Panel on Climate Change’s (IPCC) fourth assessment report (AR4).

The study’s focus was to analyze global temperature and sea level data for the past two decades and compare them to climate projections made in the IPCC’s  AR3 and AR4. The authors denote that the present overall global warming trend of 0.16°C per decade matches well with the best estimates of the IPCC, particularly if short-term variable effects of events such as El Nino-Southern Oscillation, solar variability, and volcanic activity are taken into consideration.

Sea level rise, based upon satellite altimeter measurements, however, differs greatly from the IPCC’s AR3 and AR4 projections. The sea level rise rate specified in this study is 3.2 mm/year, and is about 60% greater than the rate projected in the IPCC AR3 and AR4.  The authors also clearly state that the increased rate in sea level rise is not due to multi-decadal internal variability in the climate system, nor do other non-climatic components like groundwater extraction or reservoir water storage have an impact on data comparisons.

Stefan Rahmstorf, lead author of the study, stated: “This study shows once again that the IPCC is far from alarmist, but in fact has under-estimated the problem of climate change. That applies not just for sea-level rise, but also to extreme events and the Arctic sea-ice loss.”

Because climate projections should be a significant part of decision-making processes relating to climate change, it is essential that we know how past projections compare to accumulating observational data.

Read the Journal article: Comparing Climate Projections to Observations Up to 2011

Ocean Acidification and Climate Change

A news item caught my interest recently – a National Public Radio (NPR) news segment of 11/23/2012 on whether shellfish can adapt to increasingly acidic oceans (NPR shellfish link). Because UN Climate Talks opened in Doha, Qatar today, I thought it would be an appropriate time to talk about ocean acidification trends. As noted by Lauren Sommer during the NPR broadcast, “Scientists say oceans are becoming more acidic as they absorb the carbon dioxide added to the air through the burning of fossil fuels. That can be bad news for oysters, mussels and others animals that are key to the seafood industry and to the marine food web. Scientists are using the unique ocean conditions off the California coast to monitor developments”.

The first comment posted on the NPR web site page of the shellfish story tried to debunk ocean acidification. However, as noted in a second comment, data from several studies clearly show that ocean pH is decreasing. In fact, a study cited by both commentors is the Wootton, et.al., 2008 study (Wootton study link) of ocean pH which is based upon a multi-year data set. The authors of this article give a summary statement of “…our results indicate that pH decline is proceeding at a more rapid rate than previously predicted in some areas, and that this decline has ecological consequences for near shore benthic ecosystems”.

Being a geologist, I like to look at the present oceanic decline in pH in a geologic context. One of the most interesting articles in this area that I’ve found is a 2012 paper by Honisch et. al. that was published in Science (Honisch study link). The authors of this paper, 21 ocean/climate geoscientists, examined the geologic record (these authors confined their study to only approximately the past 300 million years due to the presence of pelagic calcifiers similar to those living today that make the deep-sea carbonate buffer of the modern Earth system) for events that could be associated with ocean acidification, such as mass extinctions and evolutionary turnovers among marine calcifiers. They recognized eight geological events that could be similar to what is occurring today, but state, “…Although similarities exist, no past event perfectly parallels future projections in terms of disrupting the balance of ocean carbonate chemistry—a consequence of the unprecedented rapidity of CO2 release currently taking place”.

One of the better analog events identified by the Honisch study is the Paleocene-Eocene Thermal Maximum (PETM) which began about 56 million years ago. During the PETM, global temperature rose about 5 degrees Celsius – a temperature elevation that occurred within just a few thousand years. The increased temperature probably resulted from massive additions of heat-trapping greenhouse gases into the atmosphere sourced initially by volcanic eruptions and later by destabilized methane hydrate deposits and other related events such as wide-spread forest fires and thawed permafrost. It took about 200,000 years for the earth’s systems to counteract this elevated temperature. Consequences of this climate change are wide-ranging and include occurrences such as the largest extinction among deep-sea benthic foraminifers of the past 75 million years, poleward shift of many animals and plants, redistribution of mammals over high-latitude land bridges, and organism adaptation such as smaller body size. However, to put the PETM’s massive greenhouse gas injection into the atmosphere into a context for the present day, Lee Kump, in a 2011 Scientific American article on the PETM (Kump paper link), suggests that the PETM greenhouse gas release “… was only 10 percent of the rate at which heat-trapping greenhouse gases are building up in the atmosphere today”.

As the 21 geoscience authors in the 2012 Honish study summarized, “…the current rate of (mainly fossil fuel) CO2 release stands out as capable of driving a combination and magnitude of ocean geochemical changes potentially unparalleled in at least the last ~300 My of Earth history, raising the possibility that we are entering an unknown territory of marine ecosystem change”.

Let’s hope that there is huge progress made at the UN Climate Change talks.

Alaska’s Continuing Clash of Resources

The Bristol Bay watershed in southwest Alaska is the site of an ongoing clash between mining and conservation interests. On the mining side is Northern Dynasty Minerals of British Columbia and Anglo American, an international corporation headquartered in London. Together these companies form the Pebble Partnership, and their proposed mine is known as the Pebble Mine.The opposition to Pebble Mine includes a diverse coalition of native groups, village councils, commercial fishermen, local residents, guides, and conservationists.

The Pebble Mine would develop a world-class ore body that is characterized as a porphyry copper, gold, and molybdenum mineral deposit. Because the deposit contains low-grade ore, the mine scale of operation would necessarily be large. Consequently, Pebble Mine is projected to consist of an open pit mine up to 2 miles wide and 1,700 feet deep, a related underground operation, a processing mill, and extensive tailings ponds. Because of the projected large-scale mine development, the opposition groups contend that environmental risks, particularly for the wild salmon fishery, dwarf any potential economic benefits of the mining operation.

In May of 2012, the U.S. Environmental Protection Agency (EPA) released a draft environmental assessment (EA) of the Pebble Mine-like development. The EPA was petitioned by 9 tribal governments to do the EA, and thus an end-run was made around the state bureaucracy. The EPA did conclude that significant environmental damage would result from mining activity. Foremost among these conclusions were that 55 to 87 miles of pristine streams and up to 2,500 acres of wetlands would be destroyed by mining and mine-related operations.  Significantly, the EPA also noted that there is a potential risk of the mine’s tailings ponds failing, and hence acidic water and heavy metals could be released into salmon spawning grounds. The final EA is still in progress, and so the clash continues.

Read more at: Bristol Bay Clash

The Global Energy Map Is Changing

The 2012 edition of the International Energy Agency’s (IEA) World Energy Outlook (WEO) was released on 11/12/2012. The changes in the global energy map will alter outlooks on how various countries, regions and fuels interact in the global energy system in the foreseeable future.

According to the WEO, North America leads the change in the global energy balance. “North America is at the forefront of a sweeping transformation in oil and gas production that will affect all regions of the world, yet the potential also exists for a similarly transformative shift in global energy efficiency,” said IEA Executive Director Maria van der Hoeven. “This year’s World Energy Outlook shows that by 2035, we can achieve energy savings equivalent to nearly a fifth of global demand in 2010. In other words, energy efficiency is just as important as unconstrained energy supply, and increased action on efficiency can serve as a unifying energy policy that brings multiple benefits.”

Other key points of the WEO are:

North American Oil and Gas – The growth in oil and natural gas production in the U.S. will result in a tremendous change in global energy flows. The WEO’s New Policies Scenario predicts that the U.S. will be a net exporter of natural gas by 2020 and will be almost self-sufficient in energy, in net terms, by 2035.

Fossil Fuels – Fossil fuels will remain dominant in the global energy amalgam. These fuels will probably remain supported by subsidies that jumped by almost 30% to $523 billion in 2011.

Renewables – Renewables become the world’s second-largest source of power generation by 2015 and begin to replace coal as the primary source by 2035. The increase of renewable energy, however, is dependent upon continued subsidies.

Water – Water is key to energy production. The need of water for this makes water a critical component for energy projects.

Energy Efficiency – WEO asserts that this is a huge opportunity that is being unrealized. As stated within the report by Fatih Birol, IEA Chief Economist and the WEO’s lead author, “Our analysis shows that in the absence of a concerted policy push, two-thirds of the economically viable potential to improve energy efficiency will remain unrealised through to 2035. Action to improve energy efficiency could delay the complete ‘lock-in’ of the allowable emissions of carbon dioxide under a 2oC trajectory – which is currently set to happen in 2017 – until 2022, buying time to secure a much-needed global climate agreement. It would also bring substantial energy security and economic benefits, including cutting fuel bills by 20% on average.”

Download the Executive Summary at: World Energy Outlook

A slide presentation of the report is at: WEO slides

Home Heating With Volcanic Heat

Volcanic heat from Icelandic volcanoes may end up heating British homes. The UK government has signed a memorandum of understanding with Iceland to further study this option. The project would be technically challenging. Electricity produced from the geothermal energy would go to the UK via an underwater cable that would be at least 620 miles long. Icelandic officials say that the project could be in place by 2020. Read more at: Icelandic Geothermal Energy

Hurricane Sandy – A Predicted Event of Climate Change

Earlier this year, a peer-reviewed paper, Physically based assessment of hurricane surge threat under climate change, (PDF bypasses Nature’s paywall) was published in the journal Nature Climate Change. The authors predicted more frequent storm surges for New York City due to the changing climate.

The abstract from the paper follows:

Storm surges are responsible for much of the damage and loss of life associated with landfalling hurricanes. Understanding how global warming will affect hurricane surges thus holds great interest. As general circulation models (GCMs) cannot simulate hurricane surges directly, we couple a GCM-driven hurricane model with hydrodynamic models to simulate large numbers of synthetic surge events under projected climates and assess surge threat, as an example, for New York City (NYC). Struck by many intense hurricanes in recorded history and prehistory, NYC is highly vulnerable to storm surges. We show that the change of storm climatology will probably increase the surge risk for NYC; results based on two GCMs show the distribution of surge levels shifting to higher values by a magnitude comparable to the projected sea-level rise (SLR). The combined effects of storm climatology change and a 1 m SLR may cause the present NYC 100-yr surge flooding to occur every 3–20 yr and the present 500-yr flooding to occur every 25–240 yr by the end of the century.

Many residents of the areas impacted by Sandy are still without power and in the most hard-hit locations probably won’t be back in their homes for quite some time. The costs of Sandy will most likely be in the billions of dollars. And – Sandy is only one of the more recent catastrophic weather events to occur globally. There is a climate crisis.

Anthropocene: Is there a new human-based geological age?

Geologists are well known for separating the geologic time scale into many time units. The most recent time division, the Holocene, has now lasted about 11,700 years, during which time the climate has been fairly stable. However, at several recent geological meetings, geologists have discussed the premise that because human activity has so irrevocably changed our planet, we have entered a new geological age. The name given to this new, human-caused epoch is the Anthropocene. The Anthropocene was most recently discussed last week at a Geological Society conference in London . Read more about this discussion at: BBC News Science and Environment’s web site.

U.S. Coal Exports

For those concerned about coal use and the environment, the U.S. Energy Administration recently released information on U.S. coal exports. A brief summary follows:

“U.S. 2012 coal exports, supported by rising steam coal exports, are expected to break their previous record level of almost 113 million tons, set in 1981. Exports for the first half of 2012 reached almost 67 million tons, surpassing most annual export volumes dating back to 1949. U.S. coal exports averaged 56 million tons per year in the decade preceding 2011. If exports continue at their current pace, the United States will export 133 million tons this year, although EIA forecasts exports of 125 million tons.”  Source: Today In Energy, U.S. Energy Information Administration, 10/23/2012. Read more at: U.S. Coal Exports