|
Skeptic Argument |
One Liner |
Paragraph |
1 |
“Climate’s changed before” |
Climate reacts to whatever forces it to change at the time; humans are now the dominant forcing. |
Natural
climate change in the past proves that climate is sensitive to an
energy imbalance. If the planet accumulates heat, global temperatures
will go up. Currently, CO2 is imposing an energy imbalance due to the
enhanced greenhouse effect. Past climate change actually provides
evidence for our climate’s sensitivity to CO2. |
2 |
“It’s the sun” |
In the last 35 years of global warming, sun and climate have been going in opposite directions |
In
the last 35 years of global warming, the sun has shown a slight cooling
trend. Sun and climate have been going in opposite directions. |
3 |
“It’s not bad” |
Negative impacts of global warming on agriculture, health & environment far outweigh any positives. |
The negative impacts of global warming on agriculture, health, economy and environment far outweigh any positives. |
4 |
“There is no consensus” |
97% of climate experts agree humans are causing global warming. |
That
humans are causing global warming is the position of the Academies of
Science from 19 countries plus many scientific organizations that study
climate science. More specifically, around 95% of active climate
researchers actively publishing climate papers endorse the consensus
position. |
5 |
“It’s cooling” |
The last decade 2000-2009 was the hottest on record. |
Empirical
measurements of the Earth’s heat content show the planet is still
accumulating heat and global warming is still happening. Surface
temperatures can show short-term cooling when heat is exchanged between
the atmosphere and the ocean, which has a much greater heat capacity
than the air. |
6 |
“Models are unreliable” |
Models successfully reproduce temperatures since 1900 globally, by land, in the air and the ocean. |
While
there are uncertainties with climate models, they successfully reproduce
the past and have made predictions that have been subsequently
confirmed by observations. |
7 |
“Temp record is unreliable” |
The warming trend is the same in rural and urban areas, measured by thermometers and satellites. |
Numerous
studies into the effect of urban heat island effect and microsite
influences find they have negligible effect on long-term trends,
particularly when averaged over large regions. |
8 |
“Animals and plants can adapt” |
Global warming will cause mass extinctions of species that cannot adapt on short time scales. |
A
large number of ancient mass extinction events have been strongly
linked to global climate change. Because current climate change is so
rapid, the way species typically adapt (eg – migration) is, in most
cases, simply not be possible. Global change is simply too pervasive and
occurring too rapidly. |
9 |
“It hasn’t warmed since 1998″ |
For global records, 2010 is the hottest year on record, tied with 2005. |
The
planet has continued to accumulate heat since 1998 – global warming is
still happening. Nevertheless, surface temperatures show much internal
variability due to heat exchange between the ocean and atmosphere. 1998
was an unusually hot year due to a strong El Nino. |
10 |
“Antarctica is gaining ice” |
Satellites measure Antarctica losing land ice at an accelerating rate. |
While
the interior of East Antarctica is gaining land ice, overall Antarctica
is losing land ice at an accelerating rate. Antarctic sea ice is
growingdespite a strongly warming Southern Ocean. |
11 |
“Ice age predicted in the 70s” |
The vast majority of climate papers in the 1970s predicted warming. |
1970s
ice age predictions were predominantly media based. The majority of
peer reviewed research at the time predicted warming due to increasing
CO2. |
12 |
“CO2 lags temperature” |
CO2 didn’t initiate warming from past ice ages but it did amplify the warming. |
When
the Earth comes out of an ice age, the warming is not initiated by CO2
but by changes in the Earth’s orbit. The warming causes the oceans to
give up CO2. The CO2 amplifies the warming and mixes through the
atmosphere, spreading warming throughout the planet. So CO2 causes
warming AND rising temperature causes CO2 rise. |
13 |
“Climate sensitivity is low” |
Net positive feedback is confirmed by many different lines of evidence. |
Climate
sensitivity can be calculated empirically by comparing past temperature
change to natural forcings at the time. Various periods of Earth’s past
have been examined in this manner and find broad agreement of a climate
sensitivity of around 3°C. |
14 |
“We’re heading into an ice age” |
Worry about global warming impacts in the next 100 years, not an ice age in over 10,000 years. |
The
warming effect from more CO2 greatly outstrips the influence from
changes in the Earth’s orbit or solar activity, even if solar levels
were to drop to Maunder Minimum levels. |
15 |
“Ocean acidification isn’t serious” |
Ocean acidification threatens entire marine food chains. |
Past
history shows that when CO2 rose sharply, this corresponded with mass
extinctions of coral reefs. Currently, CO2 levels are rising faster than
any other time in known history. The change in seawater pH over the
21st Century is projected to be faster than anytime over the last
800,000 years and will create conditions not seen on Earth for at least
40 million years.
|
16 |
“Hockey stick is broken” |
Recent studies agree that recent global temperatures are unprecedented in the last 1000 years. |
Since
the hockey stick paper in 1998, there have been a number of proxy
studies analysing a variety of different sources including corals,
stalagmites, tree rings, boreholes and ice cores. They all confirm the
original hockey stick conclusion: the 20th century is the warmest in the
last 1000 years and that warming was most dramatic after 1920. |
17 |
“Climategate CRU emails suggest conspiracy” |
A number of investigations have cleared scientists of any wrongdoing in the media-hyped email incident. |
While
some of the private correspondance is not commendable, an informed
examination of their ‘suggestive’ emails reveal technical discussions
using techniques well known in the peer reviewed literature. Focusing on
a few suggestive emails merely serves to distract from the wealth of
empirical evidence for man-made global warming. |
18 |
“Hurricanes aren’t linked to global warming” |
There is increasing evidence that hurricanes are getting stronger due to global warming. |
It
is unclear whether global warming is increasing hurricane frequency but
there is increasing evidence that warming increases hurricane
intensity. |
19 |
“Al Gore got it wrong” |
Al Gore book is quite accurate, and far more accurate than contrarian books. |
While
there are minor errors in An Inconvenient Truth, the main truths
presented – evidence to show mankind is causing global warming and its
various impacts is consistent with peer reviewed science. |
20 |
“Glaciers are growing” |
Most glaciers are retreating, posing a serious problem for millions who rely on glaciers for water. |
While
there are isolated cases of growing glaciers, the overwhelming trend in
glaciers worldwide is retreat. In fact, the global melt rate has been
accelerating since the mid-1970s. |
21 |
“It’s cosmic rays” |
Cosmic rays show no trend over the last 30 years & have had little impact on recent global warming. |
While
the link between cosmic rays and cloud cover is yet to be confirmed,
more importantly, there has been no correlation between cosmic rays and
global temperatures over the last 30 years of global warming. |
22 |
“1934 – hottest year on record” |
1934 was one of the hottest years in the US, not globally. |
1934
is the hottest year on record in the USA which only comprises 2% of the
globe. According to NASA temperature records, the hottest year on
record globally is 2005. |
23 |
“It’s freaking cold!” |
A local cold day has nothing to do with the long-term trend of increasing global temperatures. |
Since
the mid 1970s, global temperatures have been warming at around 0.2
degrees Celsius per decade. However, weather imposes its own dramatic
ups and downs over the long term trend. We expect to see record cold
temperatures even during global warming. Nevertheless over the last
decade, daily record high temperatures occurred twice as often as record
lows. This tendency towards hotter days is expected to increase as
global warming continues into the 21st Century. |
24 |
“Sea level rise is exaggerated” |
A variety of different measurements find steadily rising sea levels over the past century. |
Sea
levels are measured by a variety of methods that show close agreement –
sediment cores, tidal gauges, satellite measurements. What they find is
sea level rise has been steadily accelerating over the past century. |
25 |
“It’s Urban Heat Island effect” |
Urban and rural regions show the same warming trend. |
While urban areas are undoubtedly warmer than surrounding rural areas, this has had little to no impact on warming trends. |
26 |
“Medieval Warm Period was warmer” |
Globally averaged temperature now is higher than global temperature in medieval times. |
While
the Medieval Warm Period saw unusually warm temperatures in some
regions, globally the planet was cooler than current conditions. |
27 |
“Mars is warming” |
Mars is not warming globally. |
Martian
climate is primarily driven by dust and albedo and there is little
empirical evidence that Mars is showing long term warming. |
28 |
“Arctic icemelt is a natural cycle” |
Thick arctic sea ice is undergoing a rapid retreat. |
Arctic
sea ice has been retreating over the past 30 years. The rate of retreat
is accelerating and in fact is exceeding most models’ forecasts. |
29 |
“Increasing CO2 has little to no effect” |
The strong CO2 effect has been observed by many different measurements. |
An
enhanced greenhouse effect from CO2 has been confirmed by multiple
lines of empirical evidence. Satellite measurements of infrared spectra
over the past 40 years observe less energy escaping to space at the
wavelengths associated with CO2. Surface measurements find more downward
infrared radiation warming the planet’s surface. This provides a
direct, empirical causal link between CO2 and global warming. |
30 |
“Oceans are cooling” |
The most recent ocean measurements show consistent warming. |
Early
estimates of ocean heat from the Argo showed a cooling bias due to
pressure sensor issues. Recent estimates of ocean heat that take this
bias into account show continued warming of the upper ocean. This is
confirmed by independent estimates of ocean heat as well as more
comprehensive measurements of ocean heat down to 2000 metres deep. |
31 |
“Human CO2 is a tiny % of CO2 emissions” |
The natural cycle adds and removes CO2 to keep a balance; humans add extra CO2 without removing any. |
The
CO2 that nature emits (from the ocean and vegetation) is balanced by
natural absorptions (again by the ocean and vegetation). Therefore human
emissions upset the natural balance, rising CO2 to levels not seen in
at least 800,000 years. In fact, human emit 26 gigatonnes of CO2 per
year while CO2 in the atmosphere is rising by only 15 gigatonnes per
year – much of human CO2 emissions is being absorbed by natural sinks. |
32 |
“IPCC is alarmist” |
Numerous papers have documented how IPCC predictions are more likely to underestimate the climate response.
|
The
IPCC lead authors are experts in their field, instructed to fairly
represent the full range of the up-to-date, peer-reviewed literature.
Consequently, the IPCC reports tend to be cautious in their conclusions.
Comparisons to the most recent data consistently finds that climate
change is occurring more rapidly and intensely than indicated by IPCC
predictions.
|
33 |
“Water vapor is the most powerful greenhouse gas” |
Rising CO2 increases atmospheric water vapor, which makes global warming much worse.
|
Water
vapour is the most dominant greenhouse gas. Water vapour is also the
dominant positive feedback in our climate system and amplifies any
warming caused by changes in atmospheric CO2. This positive feedback is
why climate is so sensitive to CO2 warming.
|
34 |
“Polar bear numbers are increasing” |
Polar bears are in danger of extinction as well as many other species. |
While
there is some uncertainty on current polar bear population trends, one
thing is certain. No sea ice means no seals which means no polar bears.
With Arctic sea ice retreating at an accelerating rate, the polar bear
is at grave risk of extinction |
35 |
“CO2 limits will harm the economy” |
The benefits of a price on carbon outweigh the costs several times over.
|
Economic
assessments of proposed policy to put a price on carbon emissions are
in widespread agreement that the net economic impact will be minor. The
costs over the next several decades center around $100 per average
family, or about 75 cents per person per day, and a GDP reduction of
less than 1%.
|
36 |
“It’s not happening” |
There are many lines of evidence indicating global warming is unequivocal.
|
There
are many lines of independent empirical evidence for global warming,
from accelerated ice loss from the Arctic to Antarctica to the poleward
migration of plant and animal species across the globe.
|
37 |
“Greenland was green” |
Other parts of the earth got colder when Greenland got warmer. |
The
Greenland ice sheet has existed for at least 400,000 years. There may
have been regions of Greenland that were ‘greener’ than today but this
was not a global phenomenon. |
38 |
“Greenland is gaining ice” |
Greenland on the whole is losing ice, as confirmed by satellite measurement. |
While
the Greenland interior is in mass balance, the coastlines are losing
ice. Overall Greenland is losing ice mass at an accelerating rate. From
2002 to 2009, the rate of ice mass loss doubled. |
39 |
“CO2 is not a pollutant” |
Through its impacts on the climate, CO2 presents a danger to public health and welfare, and thus qualifies as an air pollutant
|
While
there are direct ways in which CO2 is a pollutant (acidification of the
ocean), its primary impact is its greenhouse warming effect. While the
greenhouse effect is a natural occurence, too much warming has severe
negative impacts on agriculture, health and environment.
|
40 |
“CO2 is plant food” |
The effects of enhanced CO2 on terrestrial plants are variable and complex and dependent on numerous factors
|
The effects of enhanced CO2 on terrestrial plants are variable and complex and dependent on numerous factors
|
41 |
“Other planets are warming” |
Mars and Jupiter are not warming, and anyway the sun has recently been cooling slightly. |
There
are three fundamental flaws in the ‘other planets are warming’
argument. Not all planets in the solar system are warming. The sun has
shown no long term trend since 1950 and in fact has shown a slight
cooling trend in recent decades. There are explanations for why other
planets are warming. |
42 |
“Arctic sea ice has recovered” |
Thick arctic sea ice is in rapid retreat. |
Arctic
sea ice has been steadily thinning, even in the last few years while
the surface ice (eg – sea ice extent) increased slightly. Consequently,
the total amount of Arctic sea ice in 2008 and 2009 are the lowest on
record. |
43 |
“There’s no empirical evidence” |
There are multiple lines of direct observations that humans are causing global warming. |
Direct
observations find that CO2 is rising sharply due to human activity.
Satellite and surface measurements find less energy is escaping to space
at CO2 absorption wavelengths. Ocean and surface temperature
measurements find the planet continues to accumulate heat. This gives a
line of empirical evidence that human CO2 emissions are causing global
warming. |
44 |
“We’re coming out of the Little Ice Age” |
Scientists have determined that the factors which caused the Little Ice Age cooling are not currently causing global warming
|
The
main driver of the warming from the Little Ice Age to 1940 was the
warming sun with a small contribution from volcanic activity. However,
solar activity leveled off after 1940 and the net influence from sun and
volcano since 1940 has been slight cooling. Greenhouse gases have been
the main contributor of warming since 1970.
|
45 |
“There’s no correlation between CO2 and temperature” |
There is long-term correlation between CO2 and global temperature; other effects are short-term. |
Even
during a period of long term warming, there are short periods of
cooling due to climate variability. Short term cooling over the last few
years is largely due to a strong La Nina phase in the Pacific Ocean and
a prolonged solar minimum. |
46 |
“It cooled mid-century” |
Mid-century cooling involved aerosols and is irrelevant for recent global warming. |
There
are a number of forcings which affect climate (eg – stratospheric
aerosols, solar variations). When all forcings are combined, they show
good correlation to global temperature throughout the 20th century
including the mid-century cooling period. However, for the last 35
years, the dominant forcing has been CO2. |
47 |
“CO2 was higher in the past” |
When CO2 was higher in the past, the sun was cooler. |
When
CO2 levels were higher in the past, solar levels were also lower. The
combined effect of sun and CO2 matches well with climate. |
48 |
“It warmed before 1940 when CO2 was low” |
Early 20th century warming is due to several causes, including rising CO2. |
Early
20th century warming was in large part due to rising solar activity and
relatively quiet volcanic activity. However, both factors have played
little to no part in the warming since 1975. Solar activity has been
steady since the 50′s. Volcanoes have been relatively frequent and if
anything, have exerted a cooling effect. |
49 |
“Global warming stopped in 1998,1995, 2002,2007, 2010, ????” |
Global temperature is still rising and 2010 was the hottest recorded.
|
2007′s
dramatic cooling is driven by strong La Nina conditions which
historically has caused similar drops in global temperature. It is also
exacerbated by unusually low solar activity.
|
50 |
“Satellites show no warming in the troposphere” |
The most recent satellite data show that the earth as a whole is warming. |
Satellite
measurements match model results apart from in the tropics. There is
uncertainty with the tropical data due to how various teams correct for
satellite drift. The U.S. Climate Change Science Program concludes the
discrepancy is most likely due to data errors. |
51 |
“It’s aerosols” |
Aerosols have been masking global warming, which would be worse otherwise. |
The global dimming trend reversed around 1990 – 15 years after the global warming trend began in the mid 1970′s. |
52 |
“It’s El Niño” |
El Nino has no trend and so is not responsible for the trend of global warming. |
The
El Nino Southern Oscillation shows close correlation to global
temperatures over the short term. However, it is unable to explain the
long term warming trend over the past few decades. |
53 |
“2009-2010 winter saw record cold spells” |
A cold day in Chicago in winter has nothing to do with the trend of global warming. |
The
cold snap is due to a strong phase of the Arctic Oscillation. This is
causing cool temperatures at mid-latitudes (eg – Eurasia and North
America) and warming in polar regions (Greenland and Arctic Ocean). The
warm and cool regions roughly balance each other out with little impact
on global temperature. |
54 |
“It’s a natural cycle” |
No known natural forcing fits the fingerprints of observed warming except anthropogenic greenhouse gases. |
A
natural cycle requires a forcing, and no known forcing exists that fits
the fingerprints of observed warming – except anthropogenic greenhouse
gases. |
55 |
“Mt. Kilimanjaro’s ice loss is due to land use” |
Most glaciers are in rapid retreat worldwide, notwithstanding a few complicated cases. |
Mount
Kilimanjaro’s shrinking glacier is complicated and not due to just
global warming. However, this does not mean the Earth is not warming.
There is ample evidence that Earth’s average temperature has increased
in the past 100 years and the decline of mid- and high-latitude glaciers
is a major piece of evidence. |
56 |
“There’s no tropospheric hot spot” |
We see a clear “short-term hot spot” – there’s various evidence for a “long-term hot spot”. |
Satellite
measurements match model results apart from in the tropics. There is
uncertainty with the tropic data due to how various teams correct for
satellite drift. The U.S. Climate Change Science Program conclude the
discrepancy is most likely due to data errors. |
57 |
“It’s not us” |
Multiple sets of independent observations find a human fingerprint on climate change. |
The human
fingerprint in global warming is evident in multiple lines of empirical
evidence – in satellite measurements of outgoing infrared radiation, in
surface measurements of downward infrared radiation, in the cooling
stratosphere and other metrics. |
58 |
“It’s Pacific Decadal Oscillation” |
The PDO shows no trend, and therefore the PDO is not responsible for the trend of global warming. |
PDO
as an oscillation between positive and negative values shows no long
term trend, while temperature shows a long term warming trend. When the
PDO last switched to a cool phase, global temperatures were about 0.4C
cooler than currently. The long term warming trend indicates the total
energy in the Earth’s climate system is increasing due to an energy
imbalance. |
59 |
“IPCC were wrong about Himalayan glaciers” |
Glaciers are in rapid retreat worldwide, despite 1 error in 1 paragraph in a 1000 page IPCC report.
|
The
IPCC error on the 2035 prediction was unfortunate and it’s important
that such mistakes are avoided in future publications through more
rigorous review. But the central message of the IPCC AR4, is confirmed
by the peer reviewed literature. The Himalayan glaciers are of vital
importance, providing drinking water to half a billion people.
Satellites and on-site measurements are observing that Himalayan
glaciers are disappearing at an accelerating rate.
|
60 |
“Scientists can’t even predict weather” |
Weather and climate are different; climate predictions do not need weather detail. |
Weather
is chaotic, making prediction difficult. However, climate takes a long
term view, averaging weather out over time. This removes the chaotic
element, enabling climate models to successfully predict future climate
change. |
61 |
“Greenhouse effect has been falsified” |
The greenhouse effect is standard physics and confirmed by observations. |
The
atmosphere of the Earth is less able to absorb shortwave radiation from
the Sun than thermal radiation coming from the surface. The effect of
this disparity is that thermal radiation escaping to space comes mostly
from the cold upper atmosphere, while the surface is maintained at a
substantially warmer temperature. This is called the “atmospheric
greenhouse effect”, and without it the Earth’s surface would be much
colder. |
62 |
“2nd law of thermodynamics contradicts greenhouse theory” |
The 2nd law of thermodynamics is consistent with the greenhouse effect which is directly observed. |
The
atmosphere of the Earth is less able to absorb shortwave radiation from
the Sun than thermal radiation coming from the surface. The effect of
this disparity is that thermal radiation escaping to space comes mostly
from the cold upper atmosphere, while the surface is maintained at a
substantially warmer temperature. This is called the “atmospheric
greenhouse effect”, and without it the Earth’s surface would be much
colder. |
63 |
“The science isn’t settled” |
That human CO2 is causing global warming is known with high certainty & confirmed by observations. |
Science
is never 100% settled – science is about narrowing uncertainty.
Different areas of science are understood with varying degrees of
certainty. For example, we have a lower understanding of the effect of
aerosols while we have a high understanding of the warming effect of
carbon dioxide. Poorly understood aspects of climate change do not
change the fact that a great deal of climate science is well understood. |
64 |
“Clouds provide negative feedback” |
Evidence is building that net cloud feedback is likely positive and unlikely to be strongly negative. |
Although
the cloud feedback is one of the largest remaining uncertainties in
climate science, evidence is building that the net cloud feedback is
likely positive, and unlikely to be strongly negative. |
65 |
“Sea level rise predictions are exaggerated” |
Sea level rise is now increasing faster than predicted due to unexpectedly rapid ice melting. |
Observed
sea levels are actually tracking at the upper range of the IPCC
projections. When accelerating ice loss from Greenland and Antarctica
are factored into sea level projections, the estimated sea level rise by
2100 is between 75cm to 2 metres. |
66 |
“It’s the ocean” |
The oceans are warming and moreover are becoming more acidic, threatening the food chain. |
Oceans are warming across the globe. In fact, globally oceans are accumulating energy at a rate of 4 x 1021
Joules per year – equivalent to 127,000 nuclear plants (which have an
average output of 1 gigawatt) pouring their energy directly into the
world’s oceans. This tells us the planet is in energy imbalance – more
energy is coming in than radiating back out to space. |
67 |
“IPCC were wrong about Amazon rainforests” |
The IPCC statement on Amazon rainforests was correct, and was incorrectly reported in some media. |
The
IPCC statement on Amazon rain forests is correct. The error was
incorrect citation, failing to mention the peer-reviewed papers where
the data came from. The peer-reviewed science prior to the 2007 IPCC
report found that up to 40% of the Brazilian forest is vulnerable to
drought. Subsequent field research has confirmed this assessment. |
68 |
“Corals are resilient to bleaching” |
Globally about 1% of coral is dying out each year. |
On a
world scale coral reefs are in decline. Over the last 30-40 years 80% of
coral in the Caribbean have been destroyed and 50% in Indonesia and the
Pacific. Bleaching associated with the 1982 -1983 El-Nino killed over
95% of coral in the Galapagos Islands and the 1997-1998 El-Nino alone
wiped out 16% of all coral on the planet. Globally about 1% of coral is
dying out each year. |
69 |
“Volcanoes emit more CO2 than humans” |
Humans emit 100 times more CO2 than volcanoes. |
Volcanoes
emit around 0.3 billion tonnes of CO2 per year. This is about 1% of
human CO2 emissions which is around 29 billion tonnes per year. |
70 |
“CO2 effect is saturated” |
Direct measurements find that rising CO2 is trapping more heat. |
If
the CO2 effect was saturated, adding more CO2 should add no additional
greenhouse effect. However, satellite and surface measurements observe
an enhanced greenhouse effect at the wavelengths that CO2 absorb energy.
This is empirical proof that the CO2 effect is not saturated. |
71 |
“Greenland ice sheet won’t collapse” |
When Greenland was 3 to 5 degrees C warmer than today, a large portion of the Ice Sheet melted. |
Satellite
gravity measurements show Greenland is losing ice mass at an
accelerated rate, increasing its contribution to rising sea levels. |
72 |
“It’s methane” |
Methane plays a minor role in global warming but could get much worse if permafrost starts to melt. |
While
methane is a more potent greenhouse gas than CO2, there is over 200
times more CO2 in the atmosphere. Hence the amount of warming methane
contributes is 28% of the warming CO2 contributes. |
73 |
“CO2 has a short residence time” |
Excess CO2 from human emissions has a long residence time of over 100 years |
Individual
carbon dioxide molecules have a short life time of around 5 years in
the atmosphere. However, when they leave the atmosphere, they’re simply
swapping places with carbon dioxide in the ocean. The final amount of
extra CO2 that remains in the atmosphere stays there on a time scale of
centuries. |
74 |
“CO2 measurements are suspect” |
CO2 levels are measured by hundreds of stations across the globe, all reporting the same trend. |
CO2 levels are measured by hundreds of stations scattered across 66 countries which all report the same rising trend. |
75 |
“Humidity is falling” |
Multiple lines of independent evidence indicate humidity is rising and provides positive feedback. |
To
claim that humidity is decreasing requires you ignore a multitude of
independent reanalyses that all show increasing humidity. It requires
you accept a flawed reanalysis that even its own authors express caution
about. It fails to explain how we can have short-term positive feedback
and long-term negative feedback. In short, to insist that humidity is
decreasing is to neglect the full body of evidence. |
76 |
“500 scientists refute the consensus” |
Around 97% of climate experts agree that humans are causing global warming. |
Close
inspection of the studies alleged to refute man-made global warming
finds that many of these papers do no such thing. Of the few studies
that do claim to refute man-made global warming, these repeat well
debunked myths. |
77 |
“Neptune is warming” |
And the sun is cooling. |
Neptune’s
orbit is 164 years so observations (1950 to present day) span less than
a third of a Neptunian year. Climate modelling of Neptune suggests its
brightening is a seasonal response. Eg – Neptune’s southern hemisphere
is heading into summer. |
78 |
“Springs aren’t advancing” |
Hundreds of flowers across the UK are flowering earlier now than any time in 250 years. |
A
synthesis of nearly 400,000 first flowering records covering 405
species across the UK found that British plants are flowering earlier
now than at any time in the last 250 years. |
79 |
“Jupiter is warming” |
Jupiter is not warming, and anyway the sun is cooling. |
Jupiter’s
climate change is due to shifts in internal turbulence fueled from an
internal heat source – the planet radiates twice as much energy as it
receives from the sun. |
80 |
“It’s land use” |
Land use plays a minor role in climate change, although carbon sequestration may help to mitigate. |
Correlations
between warming and economic activity are most likely spurious. They
don’t take into account local forcing agents such as tropospheric ozone
or black carbon. Correlations are likely over-estimated since grid boxes
in both economic and climate data are not independent. Lastly, there is
significant independent evidence for warming in the oceans, snow cover
and sea ice extent changes. |
81 |
“Scientists tried to ‘hide the decline’ in global temperature” |
The
‘decline’ refers to a decline in northern tree-rings, not global
temperature, and is openly discussed in papers and the IPCC reports. |
‘Mike’s
Nature trick’ refers to the technique of plotting recent instrumental
data along with the reconstructed data. This places recent global
warming trends in the context of temperature changes over longer time
scales. “Hide the decline” refers to a decline in the reliability of
tree rings to reflect temperatures after 1960. This is known as the
‘divergence problem’ where tree ring proxies diverge from modern
instrumental temperature records after 1960, discussed in the peer
reviewed literature as early as 1995. |
82 |
“CO2 is not increasing” |
CO2 is increasing rapidly, and is reaching levels not seen on the earth for millions of years. |
Currently,
humans are emitting around 29 billion tonnes of carbon dioxide into the
atmosphere per year. Around 43% remains in the atmosphere – this is
called the ‘airborne fraction’. The rest is absorbed by vegetation and
the oceans. While there are questions over how much the airborne
fraction is increasing, it is clear that the total amount of CO2 in the
atmosphere is increasing dramatically. Current CO2 levels are the
highest in 15 million years. |
83 |
“Record snowfall disproves global warming” |
Warming leads to increased evaporation and precipitation, which falls as increased snow in winter. |
To
claim that record snowfall is inconsistent with a warming world betrays
a lack of understanding of the link between global warming and extreme
precipitation. Warming causes more moisture in the air which leads to
more extreme precipitation events. This includes more heavy snowstorms
in regions where snowfall conditions are favourable. Far from
contradicting global warming, record snowfall is predicted by climate
models and consistent with our expectation of more extreme precipitation
events. |
84 |
“They changed the name from global warming to climate change” |
‘Global warming’ and ‘climate change’ mean different things and have both been used for decades. |
There
have long been claims that some unspecificed “they” has “changed the
name from ‘global warming’ to ‘climate change’”. In reality, the two
terms mean different things, have both been used for decades, and the
only individual to have specifically advocated changing the name in this
fashion is a global warming ‘skeptic’. |
85 |
“Solar Cycle Length proves its the sun” |
The sun has not warmed since 1970 and so cannot be driving global warming. |
The
claim that solar cycle length proves the sun is driving global warming
is based on a single study published in 1991. Subsequent research,
including a paper by a co-author of the original 1991 paper, finds the
opposite conclusion. Solar cycle length as a proxy for solar activity
tells us the sun has had very little contribution to global warming
since 1975. |
86 |
“CO2 is coming from the ocean” |
The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result. |
Measurements
of carbon isotopes and falling oxygen in the atmosphere show that
rising carbon dioxide is due to the burning of fossil fuels and cannot
be coming from the ocean. |
87 |
“IPCC overestimate temperature rise” |
Monckton used the IPCC equation in an inappropriate manner. |
Lord
Monckton has taken a single equation from the IPCC, used it in an
inappropriate manner, and then attributed his results to the IPCC. This
is as if I borrowed your car, drove into a tree, and then blamed you. He
uses a method that is clearly intended to examine the long-term
response of temperature to changes in carbon dioxide, and which is never
used by the IPCC (nor should it be) to make predictions about current
temperature trends. A slight change in Lord Monckton’s methodology as of
July 2010 still does not make his method or attribution remotely
appropriate. |
88 |
“CO2 is not the only driver of climate” |
Theory, models and direct measurement confirm CO2 is currently the main driver of climate change. |
While
there are many drivers of climate, CO2 is the most dominant radiative
forcing and is increasing faster than any other forcing. |
89 |
“Peer review process was corrupted” |
An Independent Review concluded that CRU’s actions were normal and didn’t threaten the integrity of peer review. |
The
Independent Climate Change Email Review investigated the CRU
scientists’ actions relating to peer review. In one case, it judged
their strong reaction to a controversial paper was not unusual. In
another, it turned out the alleged victim had actually been spreading
malicious rumours about CRU. In a third, the allegation of collusion
fell apart when the full email exchange was examined. The Review
concluded that CRU’s actions were normal and did not threaten the
integrity of peer review. |
90 |
“Southern sea ice is increasing” |
Antarctic sea ice has grown in recent decades despite the Southern Ocean warming at the same time. |
Antarctic
sea ice has growing over the last few decades but it certainly is not
due to cooling – the Southern Ocean has shown warming over same period.
Increasing southern sea ice is due to a combination of complex phenomena
including cyclonic winds around Antarctica and changes in ocean
circulation. |
91 |
“It’s microsite influences” |
Microsite influences on temperature changes are minimal; good and bad sites show the same trend. |
Poor weather stations actually show a cooler
trend compared to well sited stations. This is due to instrumentation
changes. When this is taken into account, there’s negligible difference
between poor and well sited stations. |
92 |
“Phil Jones says no global warming since 1995″ |
Phil Jones was misquoted. |
When you read Phil Jones’ actual words, you see he’s saying thereis
a warming trend but it’s not statistically significant. He’s not
talking about whether warming is actually happening. He’s discussing our
ability to detect that warming trend in a noisy signal over a short
period. |
93 |
“Humans are too insignificant to affect global climate” |
Humans are small but powerful, and human CO2 emissions are causing global warming. |
Atmospheric
CO2 levels are rising by 15 gigatonnes per year. Humans are emitting 26
gigatonnes of CO2 into the atmosphere. Humans are dramatically altering
the composition of our climate. |
94 |
“Lindzen and Choi find low climate sensitivity” |
Lindzen and Choi’s paper is viewed as unacceptably flawed by other climate scientists. |
Lindzen’s
analysis has several flaws, such as only looking at data in the
tropics. A number of independent studies using near-global satellite
data find positive feedback and high climate sensitivity. |
95 |
“Dropped stations introduce warming bias” |
If the dropped stations had been kept, the temperature would actually be slightly higher. |
Dropped
weather stations actually show a slightly warmer trend compared to kept
stations. So the removal of these faster warming dropped stations has
actually imposed a slight cooling trend although the difference is
negligible since 1970. |
96 |
“It’s too hard” |
Scientific
studies have determined that current technology is sufficient to reduce
greenhouse gas emissions enough to avoid dangerous climate change. |
The
argument that solving the global warming problem by reducing human
greenhouse gas emissions is “too hard” generally stems from the belief
that (i) our technology is not sufficiently advanced to achieve
significant emissions reductions, and/or (ii) that doing so would
cripple the global economy. However, studies have determined that
current technology is sufficient to reduce greenhouse gas emissions the
necessary amount, and that we can do so without significant impact on
the economy. |
97 |
“It’s albedo” |
Albedo change in the Arctic, due to receding ice, is increasing global warming. |
The long term trend from albedo is that of cooling. In recent years, satellite measurements of albedo show little to no trend. |
98 |
“Tree-rings diverge from temperature after 1960″ |
This is a detail that is complex, local, and irrelevant to the observed global warming trend. |
The
divergence problem is a physical phenomenon – tree growth has slowed or
declined in the last few decades, mostly in high northern latitudes.
The divergence problem is unprecedented, unique to the last few decades,
indicating its cause may be anthropogenic. The cause is likely to be a
combination of local and global factors such as warming-induced drought
and global dimming. Tree-ring proxy reconstructions are reliable before
1960, tracking closely with the instrumental record and other
independent proxies. |
99 |
“Hansen’s 1988 prediction was wrong” |
Jim Hansen had several possible scenarios; his mid-level scenario B was right.
|
Subsequent
comparison of observations with predictions find that Hansen’s Scenario
B (which most closely matched the level of CO2 emissions) shows close
correlation with observed temperatures.
|
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