A friend of mine who works
for the EPA emailed me a link to NASA’s Earth
Observatory page pitching 2014 as the warmest year on record, and asked if “I dismiss their findings.” The
following is an edited version of my reply suggesting the Global
Average Chimera tells us precious little about the climate’s
sensitivity to CO2, and the uncertainty is far greater than the error bars
illustrated in Anthony Watts post 2014:
The Most Dishonest Year on Record.
I simply asked my friend
to consider all the factors involved in Gavin Schmidt’s making of the global
average temperature trend, and ask you all to do the same. Then decide for yourselves
the scientific value of the graph and if there was any political motivation.
1. Consider the greatest
warmth anomalies are over the Arctic Ocean because more heat is ventilating
through thinner ice. Before the Arctic Oscillation removed thick insulating sea
ice, air temperatures were declining. Read Kahl, J., et al., (1993) Absence of evidence for greenhouse warming
over the Arctic Ocean in the past 40 years. Nature
361, 335 – 337.
After subfreezing winds removed
thick ice, then air temperatures rose. Read Rigor,
I.G., J.M. Wallace, and R.L. Colony (2002), Response of Sea Ice to the Arctic
Oscillation, J. Climate, v. 15,
no. 18, pp. 2648 – 2668. They concluded, “it can be
inferred that at least part of the warming that has been observed is due
to the heat released during the increased production of new ice, and the
increased flux of heat to the atmosphere through the larger area of thin ice.”
CO2
advocates suggest CO2 leads to “Arctic amplification” arguing dark open oceans
absorb more heat. But the latest estimates show the upper 700 meter of the
Arctic Ocean are cooling (see illustration below), which again supports the
notion ventilating heat raised air temperatures. Read Wunsch,
C., and P. Heimbach, (2014) Bidecadal Thermal Changes in the Abyssal Ocean, J.
Phys. Oceanogr., http://dx.doi.org/10.1175/JPO-D-13-096.1.
So how much of the global warming trend is due to heat ventilating from a cooling Arctic
ocean???
Change in top 700 meters of Ocean Heat Content between 1993 and 2011 |
2. Consider that NOAA’s graph is
based on homogenized data. Researchers analyzing homogenization methods
reported “results cast some doubts in the
use of homogenization procedures and tend to indicate that the global
temperature increase during the last century is between 0.4°C and
0.7°C, where these two values are
the estimates derived from raw and adjusted data, respectively.”
Read Steirou, E., and Koutsoyiannis, D. (2012) Investigationof methods for hydroclimatic data homogenization.
Geophysical Research Abstracts, vol. 14, EGU2012-956-1.
So how much of the recent warming trend is due to the virtual reality of homogenized data???
3. Consider
the results from Menne. M., (2009) The U.S. HistoricalClimatology Network Monthly Temperature Data, version 2.
The Bulletin for the American Meteorological Society, in which they argued
their temperature adjustments provided a better understanding of the underlying climate trend. Notice the
“adjusted” anomalies in their graph below removes/minimizes observed cooling
trends. More importantly ask why does Menne (2009) report a cooling trend for
the eastern USA from 1895to 2007, but NASA shows a graph (below Menne’s) with a
slight warming trend for all of the USA from 1950-2014? Does that discrepancy indicate more
homogenization, or that they cherry-picked a cooler period to start their
warming trend?
4. Consider that most of the warming in North America
as illustrated by Menne 2009 (above) happened in the montane regions of the
American west. Now consider the paper Oyler (2015) Artificial amplification of warming trends across the mountains of thewestern United States, in which they conclude, “Here
we critically evaluate this network’s temperature observations and show that
extreme warming observed at higher elevations is the result of systematic
artifacts and not climatic conditions. With
artifacts removed, the network’s 1991–2012 minimum temperature trend decreases
from +1.16°C/decade
to
+0.106°C/decade.
So how much of the recent warming trend is
due to these systematic artifacts???
5. Consider that NOAA’s graph
is based on adjusted data and the fact that NOAA now
homogenizes temperature data every month and climate trends change from month
to month, and year to year. As an example, below is a graph I created from the
US Historical Climate Network Cuyamaca weather station in southern California;
a station that never altered its location or instrumentation. In 2011 the raw
data temperature trend does not differ much from the homogenized trends
(Maximum Adj.)
US Historical Network raw and homogenized maximum temperatures at Cuyamaca |
Just 2 years later, the 2011
homogenized century warming trend (in black ) increased by more than 2°F the 2015 trend
(in red.) I have archived several other similar examples of this USHCN datamanipulation. Then ask your self which is more real? The more cyclical changes
observed in non-homogenized data or the rising trend created by homogenized
virtual reality?
Cuyamaca's rapidly warming trend created by homogenization |
6.
Consider that climate change along western North America has been completely
explained by the Pacific Decadal Oscillation and the associated cycles of
ventilation and absorption of heat. Read: Johnstone and Mantua (2014) Atmospheric controls on northeast Pacific temperature variability and change, 1900–2012. Such research suggests non-homogenized
data may better represent climate reality.
Knowing that the upper 10 feet of the
oceans contain more heat than the entire atmosphere ask yourself if decadal
warming trends are simply artifacts of the redistribution of heat.
7. Consider that increasingly temperature data is now
collected at airports. A 2010 paper by Imhoff, “Remote sensing of the urban heat island effectacross biomes in the continental USA”,
published in Remote Sensing of Environment
114 (2010) 504–513 concluded that “We
find that ecological context significantly influences the amplitude of summer
daytime urban–rural temperature differences, and the largest (8 °C average) is
observed for cities built in biomes dominated by temperate broadleaf and mixed
forest. For all cities combined,
Impervious Surface Area is the primary driver for increase in temperature
explaining 70% of the total variance. On a yearly average, urban areas are substantially warmer than the non-urban fringe by 2.9
°C, except for urban areas in biomes with arid and semiarid climates.”
So how much of this recent warming
trend can be attributed to increases in
Impervious Surface Area in and around weather stations in rural, suburban
and urban settings?
8. Consider that direct
satellite observations show lost vegetation has a warming effect, and
transitions from forest to shrub land, or grassland to urban area raise skin
surface temperatures by 10 to 30°F.
Satellite data reveals the canopies of the world’s forests averaged
about 86°F, and in the shade beneath the canopy, temperatures are much lower.
Grassland temperatures are much higher, ranging from 95 to 122°F, while the
average temperatures of barren ground and deserts can reach 140°F. Read Mildrexler,
D., et al. (2011) A global comparison betweenstation air temperatures and MODIS land surface temperatures reveals thecooling role of forests. J. Geophys. Res., 116,
G03025, doi:10.1029/2010JG001486.
Ask yourself, “how much of the warming trend is due to population effects
that remove vegetation??” How much is due to citizens of poorer nations
removing trees and shrubs for fuel for cooking and heating or slash and burn
agriculture?
9. Consider that neither of the satellite data sets suggest
2014 was the warmest ever recorded.
Global temperature trend from satellite data |
10. Consider that none of the tree ring data shows a warming that
exceeds that 1940s as exemplified by Scandinavian tree ring data (from Esper,
J. et al. (2012) Variability and extremes of
northern Scandinavian summer temperatures over the past two millennia. Global
and Planetary Change 88–89 (2012) 1–9.)
Tree ring and Scandinavian instrumental data show show warmest decade in the 1930s |
Consider international tree ring experts have concluded, “No current tree ring
based reconstruction of extratropical Northern Hemisphere temperatures that
extends into the 1990s captures the full range of late 20th century warming
observed in the instrumental record.” Read Wilson R., et
al., (2007) Matter of divergence: tracking recent warming at hemispheric scalesusing tree-ring data. Journal of Geophysical Research–A, 112, D17103, doi:
10.1029/2006JD008318.
In summary, after acknowledging the other factors contributing to
local temperature change, and after recognizing that data homogenization has
lowered the peak warming of the 30s through the 50s in many original data sets
by as much as 2 to 3°F, (a peak warming also observed in many proxy data sets less
tainted by urbanization effects), ask yourself, does NOAA’s graph and record 2014 temperatures really tell us anything
about climate sensitivity or heat accumulation from rising CO2? Or does it
tell us more about climate politics and data manipulation?
NOAA's Global Temperature Trend: What does it tell us about the causes? |