Dr James Renwick of NIWA responds to your questions relating to Climate Change. WeatherWatch.co.nz thanks Dr Renwick for taking the time to answer the many questions sent in by our readers.
Dr Renwick’s replies are in italics.
1. I recently read an article about the fact that the sun appears to be going into a period of hibernation, that is the activity levels are dropping. The article suggested that this will result in a period of significant cooling on earth. Doesn’t it seem strange that the sun is responsible for cooling but not warming?
Maybe the proponents of global warming don’t want to recognise that as it doesn’t suit their purpose?
1. Is their any influence from the sun?
1. How can a tax payment on climate change stop global warming?
1. It seems to me that there are more earthquakes, more frequently or being reported of more? Can you please give me more insight into this as, Melbourne just had one today, they’re happening what feels like all over NZ. Surely more natural disasters are impacting because of climate change perhaps.
1. Is the recent volcanic activity expected to have a climatic change or even a weather impact?
1. In geology terms, weather patterns have existed for countless millions of years however in technical terms, reliable weather gauges and meters have existed for less than one hundred years. With such a huge gap, how can scientists promote the certainty of climate change without conclusive data?
2. While people choose to live on flood plains, reclaimed swamps, past hillside slips, eroding coastlines, sand starved islands, etc, we will hear about extreme weather, climate change or even global warming. This century would be a speck on a geology time line so how do scientists determine that we are entering another ice age when we could be just leaving it?
1. Does the activity of the sun influence our temperature on earth and if so can the cooling down of the sun or a quiet period help us with Global Warming?
1. I’ve been reading lately that many of the planets in the solar system are heating up. Do those that believe we are contributing to climate change, think that maybe they were off the mark – given that other planets and moons are also warming up?
Benny Pieser from John Moores University was quoted as saying “Perhaps it is a fluke”. That to me is a cop-out – multiple planets/moons experiencing the same thing at the same time. For those that are so certain that the science stands behind them on it, the fluke comment really isn’t a scientific response.
I’m interested in Dr Renwick’s answer in what correlation there is/is not between earth’s warming and other planets and moons in our solar system.
Fact: NASA discovered planets are heating up.
Fact: Earth is heating up
Claim: Humans are largely responsible for earth heating up.
Question: If other planets are heating up, why are we responsible for earth?
Given the questioning of global and regional temperature records, in your opinion, what is the best data set that unequivocally shows that the current warming (since the 1980s) is exceptional and outside the limits of natural variability experienced over the past 100 years, or indeed 1000 years?
2. During the 80s and 90s, and early this century, various climate models predicted that global temperatures would increase significantly due to rising CO2. Over the past decade, however, (since 1998) it is generally acknowledged there has been increasing divergence of temperature records from model predictions, with no increase in global temperature, and possibly a decrease.
Given the lack of warming over the past decade, at what point do you think the climate models should be reassessed and the relationship between CO2 and temperature questioned?
3. Predictions of catastrophic events resulting from warmer temperatures include rapidly rising sea levels, increased number and severity of cyclones/hurricanes, and increased extremes of both flooding and drought. Yet throughout this current warming period (ie past 30 years) the data indicate little change in the rate or frequency of these predicted events or indeed, movements opposite to predicted direction. For example the rate of sea level rise, according to Colorado data, is in fact slowing (despite their recent adjustment for land rise). Similarly for cyclone data, there does not appear to be any detectable increase in cyclone severity or total cyclone energya, although possibility an increase in number due to better detection of smaller cyclones. Measures of cyclone energy actually appear to be inversely related to warming. It was also predicted that snow cover would decrease (and for children in the UK, it was claimed a few years ago that snow would be a thing of the past). Yet snow extent in the northern hemisphere has not decreased; since 1967 it has marginally increased.
How much credence do you give to predictions of catastrophic changes – that is changes outside of the extremes already experienced over the past century?
In your opinion, do you think data from reactive global surrogates for temperature, such as rate of sea level rise and extent of snow cover, are more useful measures than the temperature record?
4. CO2 has been identified by climate scientists who believe the current warming is exceptional as the primary driver of temperature, with changes in sun activity contributing only a small amount. Yet recent data show increasing divergence-of-fit between CO2 levels and temperature, but a strong correlation with sun cycle activity. Very recent publications provide very good data showing a marked decrease in sun activity and the authors predict that this could impact negatively on global temperatures and be clearly noticeable in about a decade, at the beginning of sun cycle 25 – which may not eventuate – and possibly extend for several decades.
Do you think predictions of a marked cooling in the relatively near future, based on observations of patterns of sun activity, have any foundation?
5. NZ’s EST and the Australian proposed carbon tax are based on the premise that CO2 is the driver of climate change and reductions in man-made CO2 emissions will stop and hopefully reduce temperature increase. My rudimentary calculations show that this is impossible as any change in temperature would not be measurable with current instruments, and would be meaningless when measured against a background of natural variability.
Has NIWA calculated the net effect of our ETS on predicted global temperatures, and has NIWA calculated the effect on global temperature if our scheme was world wide?
Why are only selective weather events ‘consistent’ with global warming but not others? Is this because those events that are supposedly ‘consistent’ actually lack data to show otherwise?
I remember statements made some years ago that warming was almost certainly the driver of Katrina and that we would see many more such storms. As we now know that was not true. So, seems to me that the only way of properly handling uncertainty is not not speculate but to collect data.
The second point concerns the statement that the Greenland ice sheet lost more mass last year than any year in the last decade. So question is: If the Greenland ice sheet is losing mass faster than at any time over the past 10 years, where is the water going to?
The predictions have been loud and clear that the loss will increase sea level. Yet the data show otherwise. The rate of sea level rise is decreasing – according to 5 recording systems. So something doesn’t fit?
Again, our big thanks to Dr Renwick for taking the time to answer the many questions. Feel free to discuss in the comments section below. Comments that involve nasty personal attacks will not be published.
on 18/07/2011 11:44pm
Thank you Weatherwatch and Dr Renwick…
One thing to note: The links supplied end up at a webmail login for trnnz.co.nz (The Radio Network) 🙂 I’ve managed to get to the articles…but I’m a geek so I know how to strip out the mail portion.
I appreciate Dr Renwick’s responses, however I still remain unconvinced.
I see the answers re: the sun’s output is decreasing, if anything.
One question this brought to my mind is, what about the sun’s size? I’ve seen articles that the sun is increasing in size – so if the output is dropping but the size is increasing, would this not still have a heating effect on the earth?
The whole subject is fascinating from a skeptic point of view 🙂
on 18/07/2011 11:52pm
Thanks Chris – the links are all fixed now, apologies for that.
Dr Renwick is overseas for the next few weeks but we’ll definitely raise your question with him next time we speak. Great that you’re enjoying the debate!
– WeatherWatch Weekends
on 19/07/2011 12:07am
That would be super 🙂
Is there a way to get email notifications when new replies are made to posts or do I need to keep tracking this one?
on 19/07/2011 12:19am
You’ll need to keep tracking this one Chris – but if we get James to respond we’ll put this back on the homepage. In fact it will likely be placed back on the homepage this week but then may not appear for a few weeks until James is back.
on 16/07/2011 6:13am
At least both “believers” and “unbelievers” of this topic get their views aired on this site and hopefully a healthy debate.Good to see a Q&A both sides.
on 16/07/2011 3:40am
I agree, a very well done question and answer session, well done James I take my hat off to you and those who asked the questions.
It would be very good to have a perception of balance by having a person to answer questions who is from the point of view that warming or climate change is NOT from the influences of the Human race.
I would be sure that they would not come from the so called “factless propaganda brigade as suggested by RW.
Maybe we could have one of the thousands of scientists who are of the alternative views that have been silenced and are not from government funded organisations such as NIWA.
I disagree that we often hear of cold snaps in South America on the news, in fact if you look at the history of both TVNZ or worse still the BBC, we more often than not hear of the hot spots, very unbalanced in my view anyway, of course the BBC is government funded so they must follow the political agenda given them.
So WW, what do you say?
To show a balance it would be great to have the alternative point of view questioned.
Again well done James and thankyou.
on 16/07/2011 3:45am
Hi David – yes we are looking in to this now to ensure we remain fair and balanced. We have another story tomorrow with a counter discussion on Climate Change.
on 16/07/2011 2:41am
Congratulations to Jim Renwick for a simply and elegantly put series of answers. If these persuade even one person to abandon their attachment to the fact-free propaganda so freely put about by the “sceptic” industry, the exercise will have been worthwhile.
For those who never look at these reports, the NOAA one for June is out:
Note for example how the red temp. anomalies in South America outweigh the blue ones – the media are very fond of publishing “cold snap” stories from there, with never a mention of other parts that are roasting in above-normal temperatures. June 2011 was the 316th (or thereabouts) consecutive month with global means above the 20th century mean.
on 16/07/2011 8:44am
As Jim said, you get places with hotter than normal, and on the other side of the weather system that caused that you can get a place that is colder than normal
the Net effect will be no change (they cancel each other out).Thats on a regional scale. But if the net effect globaly is increasing temperature, then that points to warning occuring to increase in green house gases (as he says, given all else being equal (e.g solar output)