“There’s undeniable data that CO2 levels and other greenhouse gases in our atmosphere are increasing. This decade, average temperatures have been rising. Temperature changes are affecting weather patterns and our climate. … when you have over 90 percent of the world’s scientists who have studied this stating that climate change is occurring and that humans play a contributing role, it’s time to defer to the experts.”
Right.
New Jersey
[my home state]
everyone of the scientists that tell us that climate change is real
The natural scientists that study the climate system are not the political scientists that study how this international problem can be solved.
mega-drought that affected that region
There was indeed a severe drought. The rest of the statements seem to be mostly politics.
We may be warming. We may be cooling.”
either cooling or warming going on
The people have died before thus this corpse cannot be murdered fallacy, which is explained above.
they never can show it
If Candidate 78 has a specific question in my field of expertise, I am happy to answer it. For a complete description of the climate system and of climate change the candidate will have to invest some effort himself. There are good books in the topic.
they were as wrong as those who now say the earth is warming
The satellite data the candidate trusted for the last trend of the last 18 years show warming of the full period of measurement. Seems inconsistent.
I remember the ’70s, we were told there was global cooling.
See above, people were studying it, there was no consensus on cooling at the time.
They’re actually adjusting the numbers
Scientists estimate the trend due to climate change from observations that also contain changes due to the way the temperature was measured.
Stations are relocated, early thermometers were not as well protected against the sun.
For the observations of the sea surface temperature measurements it is important to know that in the past they were often made by taking a bucket of water out of the sea, nowadays the water inlet of ships is often used and the last decade buoys have become important. The bucket measurements are too cold because water evaporates during the measurement, which cools the water.
The net effect of all adjustments on the global mean temperature is a reduction of the warming.
If you look at satellite data for the last 18 years, there’s been zero recorded warming,
The long term trend of the satellite data is about the same as the trend of the surface temperature. The satellites measure the temperature of the troposphere, this is influenced strongly by El Niño. Candidate 80 starts his trend computation in the super El Niño year 1998 (there is just an enormous new El Niño building up). Starting the computation of a trend with a known peak does not give you an honest estimate of the long-term trend.
some theory that’s not proven.
This is only true in the sense that nothing in science is proven, not even gravity.
The basics of climate change are solid. The impacts the candidate speaks about are a lot less certain. That is, however, not a good thing; uncertainty also means that it could be a lot worse than expected. We are taking the climate system out of a state we know reasonably well. Many things are bound to happen we did not think of. For me as a citizen, such surprises are my main reason for concern.
In every political decision one needs to take uncertainty into account. That is no reason for politicians not to do their job.
the planet that we’re going to be leaving our kids and our grandchildren may well not be habitable.
This goes too far. It will have serious consequences not to address the problem, but life on Earth will remain.
The last six years we’ve actually had mean temperatures that are cooler.”
I am sorry, but the global surface temperature was warming during the last 6 years.
Furthermore, 6 years is much too short to compute trends with confidence. The trend during this short period could also have been 4.5°C per century (HadCRUT4); that value still is within the huge confidence interval for such a short-term trend.
If candidate 37 is speaking about the temperature in the troposphere, then a warming trend of 8.5°C per century is still within the confidence interval. It is best not to compute trends over such short periods when talking about long-term global warming.
It may not be warming by the way
This conflicts with the previous correct statement of Candidate 37 that "the climate is changing".
t may be only partially man-made.
He started so well.
believe the climate is changing because there’s never been a moment where the climate is not changing.
The people have died before thus this corpse cannot be murdered fallacy, which is explained above.
almost solely attributable to manmade activities
Good that Candidate 93 does know the answer.
The question is what percentage of that, or what is due to human activity.
That question has an answer. The best estimate for the warming since 1951 is that nearly 100% is due to human influences.
“It’s really cold outside, they are calling it a major freeze, weeks ahead of normal. Man, we could use a big fat dose of global warming!” “NBC News just called it the great freeze – coldest weather in years. Is our country still spending money on the GLOBAL WARMING HOAX?”
I hope it is not necessary to reply to that.
You know in the 1920s people talked about global cooling
Candidate 45 is likely speaking about the 1970s.
During the 1970s scientists were studying whether the cooling from air pollution would lead to a stronger cooling than the warming from carbon dioxide emissions.
We now know that air pollution (aerosols) cools, but that the accumulation of carbon dioxide is the stronger effect. Contrary to some stories in the press/blogs, there was never a scientific consensus that the Earth would cool: The Myth of the 1970s Global Cooling Scientific Consensus
it’s going to start to cool at some point.
Without any specification of period and time, candidate 45 could be speaking of the autumn, but if he is speaking about the long-term warming of the climate system, that will not stop before we reduce our emissions of greenhouse gasses.
It could be warming
It is warming.
You can see that in the historical instrumental temperature data, in the rising sea level, in the temperature profile of bore holes, in satellite estimated temperatures, in the increases of precipitation, in the earlier budding of plants, in the movements of plants, insects and animal towards the poles and up mountains, in the melting of mountain glaciers, in the warming of rivers and lakes, in the shortening of the period rivers and lakes are frozen, in the decrease of the Arctic sea ice and in the snow cover on land.
So, I think before we — we need to look before we leap.
However, the question was about climate change and the candidate suggests that "nature" is a reason to wait ("look"). The listener can only get the impression that the candidate means: there was natural variability in the past, thus also now a considerable part of climate change is natural.
This is wrong.
That natural variability exists and was important in the past does not mean that it has to be important now, you have to study that. You can also not argue that people have died before, therefore this corpse was not killed, the police has to study that.
When study it, you find that the long-term warming is basically due to humans. The best estimate for the warming since 1951 is that nearly 100% is due to human influences.
This paragraph is thus highly misleading
Including the Clean Power Act. While I do think that man may have a role in our climate, I think nature also has a role.
Candidate 12 is careful not to talk about climate change, but "climate" and to say that nature has "a role", but not indicate whether this role is large or whether it is cooling or warming.
It is also well-established in scientific literature that precipitation is increasingly falling in short, intense bursts rather than long-lasting, generally lighter events.
This is true. Extreme precipitation is increasing much faster than average precipitation.
See IPCC report on extremes: http://ipcc-wg2.gov/SREX/report/
Recent trends in regional and global intense precipitation patterns: http://www.sciencedirect.com/science/article/pii/B9780123847034005013
However, this is still very much an area of ongoing research. The increase in extremes goes much faster in observations than in models. At the moment it is not clear yet whether this means that we do not understand the reasons well (models) or whether this is due to historical improvements in the way we measure precipitation.
This is the distance between Ottawa, Canada, and Myrtle Beach, S.C. cities with very different climates.
One of the reasons why climatologists prefer to work with "anomalies", deviations from the typical climate, is that anomalies are similar over large regions, especially when it comes to averages over longer periods. I guess everyone still remembers that last winter the entire East Coast was colder than usual, while the West Coast was warmer than usual.
Thus while it naturally was absolutely warmer in the South, regions of the East coast with different climates still had similar temperature anomalies, this is why a station at a given point is representative of the temperature anomaly in a large region around that point.
“Global temperature” does not exist.
A measured temperature is always an average over time and space. The thermometer is not infinitely fast and probes a finite space.
If Harris were right, you could no longer say something as simple as your bedroom being cooler than your living room. Or the moon being colder than the Earth.
They also know that calculating so-called global average temperatures to hundredths of a degree is irrational.
The reasons mentioned are some of the reasons that the uncertainty due to sampling is so "large", these reasons are already taken into account. If they would not exist, the uncertainty would be smaller.
So, the new temperature records are meaningless.
It is typical that records break the old one by a small amount. In sports often by just a hundreds of a second. That is still informative. This record would not have happened if the temperature had not increased over the last century by much more than the sampling uncertainty.
September 2014 a new marathon world record was set in Berlin. Dennis Kimetto set the world record with a time of 2:02:57, while the number two of the same race, Emmanuel Mutai, set the world second best time with 2:03:13. Two records in one race! Clearly the conditions were ideal (the temperature, the wind, the flat track profile). Had other good runners participated in this race, they may well have been faster.
It is still normal to call Dennis Kimetto the fastest marathon runner and to acknowledge his achievement.
14 one-hundredths of a degree
A large part of the work of scientists is determining how accurately we know things, in this case how accurately we know the global mean temperature. That is also where Harris got the estimate of the confidence interval ("uncertainty") from. Unfortunately, the press is less interested in this.
The mentioned uncertainty in the global mean temperature is exactly because we do not have measurements everywhere and have to estimate the mean based on a sample. This is normal statistics.
All groups computing the global mean temperature (NOAA, GISS, Berkeley Earth, Japan and the UK) have difference methods to estimate the global mean temperature and find basically the same answer for the long term trend. This sampling uncertainty is important for a monthly or yearly average, but it is not important for the long-term trend, which most people are interested in.
The U.S. government
Tom Harris means: the scientists at NOAA, whose methods are published in the scientific literature and are highly respected in the scientific community.