A week or so ago I explained how researchers had discovered that plants are a source of methane: that a new study led by Frank Keppler of the Max Planck Institute in Germany calculates that all the world's living vegetation (forests included) emit between 62 and 236 million tonnes of methane per year. This is apparently equivalent to between 10 and 30 per cent of annual global methane emissions.
Now the same researchers are claiming that their findings have been misinterpreted:
The most frequent misinterpretation we find in the media is that emissions of methane from plants are responsible for global warming. As those emissions from plants are a natural source, they have existed long before man's influence started to impact upon the composition of the atmosphere. It is the anthropogenic emissions which are responsible for the well-documented increasing atmospheric concentrations of methane since pre-industrial times. Emissions from plants thus contribute to the natural greenhouse effect and not to the recent temperature increase known as 'global warming'. Even if land use practices have altered plant methane emissions, which we did not demonstrate, this would also count as an anthropogenic source, and the plants themselves cannot be deemed responsible.
I guess this approach is consistent with the United Nations Framework Convention on Climate Change which defines 'climate change' as that which is attributable directly or indirectly to human activity, click here.
So according to Keppler et al. plants are not responsible for what they emit. I guess this means that they are not responsible either for sequesting carbon dioxide. However, we do count carbon sequestration (post 1990) in national greenhouse inventories, so shouldn't we also count methane emitted from the same plants in the inventory?
Interestingly, in the Nature paper, Keppler et al. state:
In pre-industrial times, that is, without anthropogenic emissions, the relative contribution of methane to the atmosphere by direct plant emissions may have been even larger than today. This could have far reaching implications for the interpretation of atmospheric methane levels and climate signals in the past.
If trees emit methane, that means if we want to save the world, we need to cut a tree.
But that means the fact that trees provide oxygene that we breath is wrong.
Canberra does have many trees but does that also means that if we want to decrease the amount of methane produced in Canberra, we need to cut the trees in Canberra?
thanks
If Trees emit methane they are part of the problem
Do all species of trees emit methane?
Are some better or worse?
Surely this is someting we should know before we plant.
What about other plants?
Does the CO2 plants lock up compensate?
After all CO2 lasts for 100 years methane for only 10
If methane comes from wetlands; would it come from my local lake where piles of sea grass our now washing up on shore and rotting? ( due to nutrient increases in lake water)
Thanks
Perhaps Popper is not to blame for bastardisation Ian: he did write Conjectures and Refutations, and moreover the more bloke was linguistically challenged by having to get out of Vienna ahead of Herr Hitler, who wasnt very tolerant of new ideas.
Last paper - 1988 is a tad old given developments.
There's something very wrong though with his logic - you can predict some things very well - like seasons and spatial patterns of polar and tropical climate. And they can predict the temperature growth of the last century with multiple forcings. - You will notice that there is a fair bit of noise around the mean - but nevertheless the mean trend is reproduced.
And he is mixing all sorts of differnet scales from weather to seasonal to climate change. You require different things from the models at different scales. With weather you ARE trying to predict the weather on Jan 30, 2006 - but with climate change you are NOT trying to predict the weather of Jan 30, 2030. But you are trying to predict the climatology of 2030.
And of course it also goes both ways - "overlooking a non-linear chaotic mechanism" might mean a very nasty sudden climate shift starts next week or started 10 years ago.
BTW, if IPCC use an adjustable variable for albedo (dimming effects) the model is not falsifiable, and unscientific.
PS U Christchurch is a falsity, U Canterbury is valid, methinks.
The fact that Popper has done some great work and has numerous devoted fans does not excuse the bastardisation of the English language to a point where the one word, and a verb, has two almost directly contradictory meanings. It is sloppy work and his editor is obviously to blame.
Prof. Hendrik Tennekes reflects on climate models and Popper (tks Louis)
http://meteo.lcd.lu/globalwarming/Tenneke/reflections_sceptic.html
….I protest against overwhelming pressure to adhere to the climate change dogma promoted by the adherents of IPCC.
….From this perspective, those that advocate the idea that the response of the real climate to radiative forcing is adequately represented in climate models have an obligation to prove that they have not overlooked a single nonlinear, possibly chaotic feedback mechanism that Nature itself employs.
NOAA support Tennekes and Popper
http://www.nssl.noaa.gov/users/brooks/public_html/sref/srefarticle.html
….We echo the alarm of Tennekes (1988) about the lack of vision concerning the role of humans in forecasting. Beyond that, however, we are alarmed about an equivalent lack of vision about the role of technology in forecasting. We have the opportunity to rethink fundamentally our approach to NWP. The time it will take to have models ready to take advantage of petaflop machines may well be of the same order as the time before the machines are available, perhaps a decade. If we do not start now to explore alternative uses of NWP models, we may miss or, at the very least, delay by years, the possibility of a true revolution and improvement in weather forecasting. Taking less than full advantage of both the human and machine side of the forecasting problem would be a crucial mistake.