Archive for the ‘refuting the skeptics’ Category

Record setting 2010 Greenland temperatures and long term trends

Thursday, January 20th, 2011

Year 2010 surface air temperature observations around west and south Greenland are unprecedented in the instrumental record. Year 2010 and year 2003 temperatures dwarf high yearly averages occurring in the 1920s and 1930s.

Warming and Cooling

Fig. 1. 170 years of annually resolved whole Greenland ice sheet averaged surface air temperature from a reconstruction driven by a statistical fusion of long term meteorological station data with calibrated regional climate data assimilation model output (Box et al. 2009). A pink circle denotes the record setting year 2010 value.The thick gray line is a 31 year two-tailed Gaussian-weighted smoothing of the annual values. As the "boxcar" gets within 15 years of the beginning and end of the series, the "tail" that runs into the end of the series is cut off and the weighting shifts accordingly.

Over the full 171 years (1840-2010) of the reconstruction, the ice sheet average surface air temperature increased 1.26 C. The warming rate was 0.74 C/century. The recent 17 year Greenland ice sheet warming rate is 30% smaller in magnitude than a 17 year period in the 1920s. The intervening 63 year period (1932 to 1992) was cooling at -0.19 C/decade. This  cooling can be attributed to a cooling phase of the Atlantic Multidecadal Oscillation (AMO) (e.g. Schesinger et al. 1994; Trenberth et al. 2006). Cold episodes in 1983-84 and 1991-92 enhance this cooling trend and are caused primarily by major volcanic eruptions (see Box, 2002) . West Greenland is a focus of sulfate aerosol-induced cooling (see Box et al. 2009). Another contributor to the 1932 to 1992 cooling is global dimming, that is, cooling at the surface induced by increases in atmospheric aerosols. Liepert et al (2002) estimated that there was globally a reduction of about 4% in solar radiation reaching the ground between 1961 and 1990. The Wikipedia Global Dimming article is worth reading. The recent (post-1994) warming, is attributable to: 1.) a growing absence of sulfate cooling because there has not been a major volcanic eruption since 1991; 2) recent warming phase of AMO; 3) an apparent  reversal of the global dimming trend; and 4) ongoing and intensifying anthropogenic global warming (AWG), the elephant in the room, owing to a dominance of enhanced greenhouse effect despite other anthropogenic cooling factors such as aerosols and contrails (IPCC, 2007). The primary factor responsible for the warming trend is very likely to be AWG (IPCC, 2007).

Fig. 2. Three long term Greenland meteorological station records, illustrating the long term time series of yearly-average temperatures. Triangles denote record setting values coinciding in 2010. Also interesting to note is the strong 1983-1984 El Chichon volcanic cooling (see Box 2002).

Refuting Denial

It is scientific to question if year 2010 record setting temperatures are real or due to some spurious aspect of the measurements. Former television meteorologist Anthony Watts, for one, expended quite a lot of effort to discredit apparent record setting 2010 temperatures in Nuuk, Greenland. However, Watts seems in error, as one would not expect the same pattern at other locations and in independent periods of time (Fig. 2), if the Nuuk 2010 temperatures are spurious. Rather, record high temperatures are evident at other Greenland stations in the same months, for example, in May, August, September, November, December 2010. Watts implicates the fact that the Nuuk measurements are near an airport to discredit the anomalous year 2010 values. Heat spewing from airplanes seems a valid concern and incidentally Aasiaat measurements are also from the grounds of an airport. However, the Prince Christian Sound (a.k.a. Prins Christian Sund) data are not obtained from near any airport (J. Cappelen, DMI, personal communication).

Acknowledgement

We are fortunate to have continuous temperature records from Greenland’s capital Nuuk beginning in 1866 in addition to century-plus records from other locations in Greenland (Box 2002; Vinther et al. 2006; Cappelen 2010; Box et al. 2009), providing instrumental climate records rivaling many of the longest records on Earth. I have used these data record and others available from the Danish Meteorological Institute and NASA to reconstruct Greenland ice sheet average surface air temperatures (see Box et al. 2009). I update the Box et al. (2009) reconstruction and make further analysis in this blog entry. This work is in preparation for my 7th consecutive annual Greenland entry for the Bulletin of the American Meteorological Society’s “State of the Climate” report published each June.

Sources

  • Box, J.E., 2002: Survey of Greenland instrumental temperature records: 1873-2001, International Journal of Climatology, 22, 1829-1847. PDF
  • Box, J.E., L. Yang, D.H. Browmich, L-S. Bai, 2009: Greenland ice sheet surface air temperature variability: 1840-2007, J. Climate, 22(14), 4029-4049, doi:10.1175/2009jcli2816.1. PDF
  • Cappelen J., 2010: DMI Monthly Climate Data Collection 1768-2009, Denmark, The Faroe 263 Islands and Greenland Dansk Meterologisk Institut Technical report No. 10-05
  • Intergovernmental Panel on Climate Change (IPCC) (2007), Climate Change 2007: The Physical Science Basis, edited by S. Solomon et al., Cambridge Univ. Press, New York.
  • Liepert, B. G. (2002), Observed reductions of surface solar radiation at sites in the United States and worldwide from 1961 to 1990, Geophys. Res. Lett., 29(10), 1421, doi:10.1029/2002GL014910.
  • Schlesinger, M.E. and Navin Ramankutty (1994): An oscillation in the global climate system of period 65-70 years. Nature, 367, Issue 6465, pp. 723-726, DOI: 10.1038/367723a
  • Trenberth, K.E. and D.J. Shea (2006): Atlantic hurricanes and natural variability in 2005. Geophysical Research Letters 33, L12704, doi:10.1029/2006GL026894 PDF
  • Vinther, B. M., K. K. Andersen, P. D. Jones, K. R. Briffa, and J. Cappelen, 2006: Extending Greenland temperature records into the late eighteenth century. J. Geophys. Res., 111, D11105,
    doi:10.1029/2005JD006810.

Global Warming Petition Project supported by an underwhelming 0.12% climatologists

Sunday, October 18th, 2009

Of the 31,478 scientist signatories to the Global Warming Petition Project under Qualifications of Signatories, only 0.12% or 39 designate having their primary education in “Climatology”. That’s 12 people in 1000. Un-credible.

Climate 2030: A National Blueprint for a Clean Energy Economy

Sunday, September 6th, 2009

from Union of Concerned Scientists…

“Reducing oil dependence. Strengthening energy security. Creating jobs. Tackling global warming. Addressing air pollution. Improving our health. The United States has many reasons to make the transition to a clean energy economy. What we need is a comprehensive set of smart policies to jump-start this transition without delay and maximize the benefits to our environment and economy. Climate 2030: A National Blueprint for a Clean Energy Economy (“the Blueprint”)
answers that need.

To help avoid the most dangerous consequences of climate change, ranging from extreme heat, droughts, and storms to acidifying oceans and rising sea levels, the United States must play a lead role and begin to cut its heat-trapping emissions today—and aim for at least an 80 percent drop from 2005 levels by 2050. Blueprint policies lower U.S. heat-trapping emissions to meet a cap set at 26 percent below 2005 levels in 2020, and 56 percent below 2005 levels in 2030.

The nation achieves these deep cuts in carbon emissions while saving consumers and businesses $465 billion annually by 2030. The Blueprint also builds $1.7 trillion in net cumulative savings between 2010 and 2030. Blueprint policies stimulate significant consumer, business, and government investment in new technologies and measures by 2030. The resulting savings on energy bills from reductions in electricity and fuel use more than offset the costs of these additional investments. The result is net annual savings for households, vehicle owners, businesses, and industries of $255 billion by 2030.

Under the Blueprint, every region of the country stands to save billions. Households and businesses—even in coal-dependent regions—will share in these savings.

Net Consumer and Business Savings (by Census Region in 2030)

Clean Energy, Green Jobs, progress, US competiveness

Sunday, September 6th, 2009

Anti-science climate change deniers are slowing progress that will leave the US behind economically/technlogically. Though it is obvious why clean energy will create next-generation jobs for Americans while stimulating the US economy, for further reading, see this Union of Concerned Scientists article.

Science academies’ statement on climate change

Sunday, September 6th, 2009

Science academies’ statement on climate change “It is essential that world leaders agree on emissions reductions needed to combat negative consequences of anthropogenic climate change,” national science academies from 13 countries declared in a joint statement issued on 11 June [2009]. The statement, issued by the academies of the G8 countries—including England, France, Russia, and the United States—and five other countries (Brazil, China, India, Mexico, and South Africa), came in advance of a G8 meeting in Italy in July and prior to United Nations Framework Convention on Climate Change (UNFCCC) negotiations in Denmark in December.
“The G8+5 should lead the transition to an  energy efficient and  low-carbon world economy, and foster innovation and research and development for both mitigation and adaptation technologies,” the statement noted. The academies urged governments to agree at the UNFCCC negotiations to adopt a long-term global goal and short-term emissions reduction targets so that by 2050 global emissions would be reduced by about 50% from 1990 levels.

The academies also called for a significant increase in fundamental international research on climate,  low- carbon, and  climate- resilient technologies, and on ways to protect natural systems in the face of climate change. “The need for urgent action to address climate change is now indisputable,” according to the statement.

Citation: Showstack, R. (2009), In Brief: Science academies’ statement on climate change, Eos Trans. AGU, 90(25), doi:10.1029/2009EO250004.

Temperatures have not been falling for over a decade, as claimed by some

Monday, April 6th, 2009

A NASA Goddard Institute for Space Studies (GISS) compilation of land and oceanic instrumental records of near-surface air temperature do not indicate a cooling trend in recent years, as recently claimed by Bob Wagner in public presentations

http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

Bear in mind that the red line indicates a multi-year average that smooths out year to year noise. The noise is the “weather” of the climate system. Climate trends should only be deduced from decadal averages or longer, not picking out individual years. Climate and weather represent different time scales. Shown here, the instrumental temperature data are aggregated in other ways, e.g. northern hemisphere, southern hemisphere. See, no cooling.

Independent analyses of the same instrumental temperature data (but with an independent/different cooling correction for growth of cities around some of the stations) have been made by the UK Climate Research Unit at School of Environmental Sciences University of East Anglia, Norwich. See an example below…

http://www.cru.uea.ac.uk/cru/data/temperature/nhshgl.gif

Here’s more information about the CRU analyses.

So, you think there’s ocean cooling?

Human-induced climate deniers have blown hard about a now obsolete study (Lyman et al, 2006) that identified a (now understood to be spurious) recent cooling trend in ocean heat content data. According to Gavin Schmidt -

“The ‘cooling’ was actually due to combination of a faulty pressure reading on a subset of the [oceanic] floats and a switch between differently-biased observing systems. The pressure error meant that the temperatures were being associated with a point higher in the ocean column than they should have been, and this (given that the ocean cools with depth) introduced a spurious cooling trend when compared to earlier data. This error may be fixable in some cases, but for the time being the suspect data has simply been removed from the analysis. The new results don’t show any cooling at all.”

Isn’t transparency nice! Sorry Bob. You’ve had it wrong. If you’d have stayed current with the science (the discrepancy was identified already nearly 2 years ago! 18 April 2007), you would not now have to retract your misleading statements.

CO2 trend not confounded by volcano, see results from other CO2 measurement sites

Saturday, April 4th, 2009

Since deniers don’t trust scientists to be careful, which they are on Mauna Loa, let’s just  throw out the Mauna Loa data for the sake of argument…  “There are dozens of other sampling stations scattered all over the globe, including one in the Antarctic, far from cities, SUVs, cement plants, and active volcanoes. It also shows the same rise [PDF], though the southern hemisphere tends to lag a few years behind the northern hemisphere, where the majority of the CO2 is produced. Here are eight others — same results.

Sorry, its all of us Joes, not the volcanoes.” – Grist

on the importance of water vapor and CO2

Friday, April 3rd, 2009

Robert Wagner (OD optometry) correctly recognizes that water vapor (what Robert Essenhigh refers to as “water gas”) is a key Greenhouse gas. Quoting the IPCC Fourth Assessment report: “Water vapor is the most important gaseous source of infrared opacity in the atmosphere, accounting for about 60% of the natural greenhouse effect for clear skies (Kiehl and Trenberth, 1997), and provides the largest positive feedback in model projections of climate change (Held and Soden, 2000).”

If Wagner read the published peer reviewed science that IPCC summarizes, he’d know that direct observations from balloon soundings show  that The average atmospheric water vapor content has increased since at least the 1980s over land and ocean as well as in the upper troposphere. The increase is broadly consistent with the extra water vapor that warmer air can hold. See IPCC 2007 Chapter 3 Section 3.4.

Meanwhile, CO2 concentrations are also increasing. Elevated CO2 concentrations have an associated net warming affect on climate. Of all the “well mixed” greenhouse gasses, CO2 has by far the largest warming effect. See figure SPM.2 in the IPCC 2007 Summary For Policy Makers.

Climate change deniers seek holes in the science instead of seeking the truth. The science by definition aims for truth.  There is no conspiracy. Climate change deniers waste the time of climate scientists and block progress. We should instead be united to protect future generations from our trashing of the environment. United we stand, divided: the rest of the world sells us technologies America should sell them.

Don’t confuse weather and climate

Friday, April 3rd, 2009

Human-induced climate change deniers confuse weather and climate.  It’s actually simple…. Climate is the long term average state. Weather is ther short term state.

Climate models predict the average state. Weather models attempt to predict the instantaneous state. Chaos theory has it that instantaneous phenomena cannot be predicted far out. Yet, it does not take a sophisticated model to predict that if humans increase the concentration of an infrared heat-trapping gas, the climate will warm. It’s that simple. The chemistry of CO2, CH4, H2O are sufficiently well established. Climate models have reproduced observed warming. Climate models wiith human chemical transformations of our atmosphere left out have no warming. See below…

http://bprc.osu.edu/~jbox/img/refuting_the_deniers/FigSPM.4_AR4WG1_climate_models_with_and_without_CO2_forcing.gif

Climate and weather are very different things

Wednesday, April 1st, 2009

Policy makers and the public need recognize the difference between weather and climate, the latter is the average state.

Grist.org:

Objection: Scientists can’t even predict the weather next week, so why should we believe what some climate model tells us about 100 years from now?

Answer: Climate and weather are very different things, and the level of predictability is comparably different.

Climate is defined as weather averaged over a period of time — generally around 30 years. This averaging smooths out the random and unpredictable behaviour of weather. Think of it as the difference between trying to predict the height of the fifth wave from now versus predicting the height of tomorrow’s high tide. The former is a challenge — to which your salty, wet sneakers will bear witness — but the latter is routine and reliable.

This is not to say it’s easy to predict climate changes. But seizing on meteorologists’ failures to cast doubt on a climate model’s 100-year projection is an argument of ignorance.

By The Way

Be aware that a cold winter does not mean Global Warming has been canceled. The climate may cool for a decade due to internal resonance of the climate, including factors such as the Atlantic Meridional Overturning circulation. After making that point, that article goes on to:

‘No distraction’

The projection does not come as a surprise to climate scientists, though it may to a public that has perhaps become used to the idea that the rapid temperature rises seen through the 1990s are a permanent phenomenon.

“We’ve always known that the climate varies naturally from year to year and decade to decade,” said Richard Wood from the UK’s Hadley Centre, who reviewed the new research for Nature.

“We expect man-made global warming to be superimposed on those natural variations; and this kind of research is important to make sure we don’t get distracted from the longer term changes that will happen in the climate (as a result of greenhouse gas emissions).”

Note that the warming trend exists whether or not the ocean forcing is included:

http://newsimg.bbc.co.uk/media/images/44617000/gif/_44617158_global_mean_temps466.gif

If you consider yourself a skeptic worth your salt, actually read the scientific publications, don’t just search for and select aspects to remove from context to attempt your debunking.

Yours sincerely,

Jason Box, Climatologist