CO2 countdown – where are we at, 385 or 395ppm?

There’s been a bit of debate as to the accuracy and validity of the CO2 Countdown clock here at Climate Shifts, so I thought i’d answer a few questions and set the record straight. The code for the original countdown was from the CO2 Clock website, which puts the current atmospheric CO2 concentration at about 397ppm.  A few people had emailed to suggest that the number of decimal places made the counter ‘unrealistic’. The author of the CO2 clock used the number of significant digits for “time lapse effect rather than empirical accuracy”, and hey, the continuing countdown made quite a few people sit up and take notice!

The CO2 clock methodology is based upon the following assumptions:

Continuously updated CO2 concentrations are derived from the montly data points provided by the in situ measurements, and currently are taken as a linear extrapolation of the previous two data points. Clock is recalibrated after the release of each new monthly data point. Future updates will take into account the seasonal trend variations in the forward interpolation.

Put simply, the source data, based upon in situ air measurements at Mauna Loa Hawaii (source here) has an inherent lag time, as the last monthly average is from May this year. The clock is recalibrated after each new month appears, but based upon the current algorithm, the data runs slightly higher than actual in the interim. We had discussed with Markin Eakin and the guys from NOAA in developing a projection based upon global synthesized air CO2 datasets (see the online Carbon Tracker for more), but in the meantime, one reader suggested that we use the CO2 Now monthly carbon tracker, an we agree.

Here are the monthly CO2 levels for August 1958-2009 based upon the Mauna Loa dataset, which should give a much more accurate reading of current atmospheric CO2 levels:

What the world needs to watch

Global warming is mainly the result of CO2 levels rising in the Earth’s atmosphere. Both atmospheric CO2 and climate change are accelerating. Climate scientists say we have years, not decades, to stabilize CO2 and other greenhouse gases.

To help the world succeed, makes it easy to see the most current CO2 level and what it means. So, use this site and keep an eye on CO2.  Invite others to do the same. Then we can do more to send CO2 in the right direction.

We felt that approaching the 400ppm level was a significant milestone (both for science and policy), and we wanted to get our readings correct and not jump the gun! Thanks again to Peter Morris and other readers who have bought this to our attention.

Where would you want to live under sea level rise? Interactive floods maps

Ever wondered where the wise investment in the property market is going to be under the IPCC projected scenarios? Check out the Sea Level Rise Explorer over at Global Warming Art:

During the twentieth century, sea level rose 20 cm. It is predicted that sea level rise will accelerate during the twenty-first century, but many model predictions still foresee a sea level rise of less than 1 additional meter by 2100.

Regardless of the time scale involved, an analogy to the previous interglacial suggests that a few degrees Celsius of sustained warming can cause enough melting to raise sea level 4-6 m before the ice sheets reach equilibrium. This level of warming is likely to be achieved or even exceeded by 2100 in the absence of intervention to combat climate change, though as above, it would take far longer to realize the full sea level change.

Sarychev volcano


This incredible photograph was  taken from the International Space Station and captures the eruption of the Sarychev Volcano, Kuril Island chain, Japan. From the NASA’s Earth Observatory:

The main column is one of a series of plumes that rose above Matua Island (48.1 degrees north latitude and 153.2 degrees east longitude) on June 12. The plume appears to be a combination of brown ash and white steam. The vigorously rising plume gives the steam a bubble-like appearance; the surrounding atmosphere has been shoved up by the shock wave of the eruption. The smooth white cloud on top may be water condensation that resulted from rapid rising and cooling of the air mass above the ash column, and is probably a transient feature (the eruption plume is starting to punch through). The structure also indicates that little to no shearing winds were present at the time to disrupt the plume. By contrast, a cloud of denser, gray ash — most probably a pyroclastic flow — appears to be hugging the ground, descending from the volcano summit. The rising eruption plume casts a shadow to the northwest of the island (bottom center). Brown ash at a lower altitude of the atmosphere spreads out above the ground at upper right. Low-level stratus clouds approach Matua Island from the east, wrapping around the lower slopes of the volcano. Only about 1.5 kilometers of the coastline of Matua Island (upper center) can be seen beneath the clouds and ash.

Off the back of this volcano is the predictable response of how volcanoes emit so much more CO2 than humans. Straight from the How to Talk to a Global Warming Skeptic guide:

Objection: One decent-sized volcanic eruption puts more CO2 in the atmosphere than a decade of human emissions. It’s ridiculous to think reducing human CO2 emissions will have any effect.

Answer: Not only is this false, it couldn’t possibly be true given the CO2 record from any of the dozens of sampling stations around the globe. If it were true that individual volcanic eruptions dominated human emissions and were causing the rise in CO2 concentrations, then these CO2 records would be full of spikes — one for each eruption. Instead, such records show a smooth and regular trend. The fact of the matter is, the sum total of all CO2 out-gassed by active volcanoes amounts to about 1/150th of anthropogenic emissions.

If you haven’t seen the Grist series in “How to talk to a climate change“, I strongly recommend checking it out. It covers pretty much every recycled argument out there (with varying degrees of sophistication ranging from ‘silly’ to ‘specious’). Hopefully somebody can now tell Jennifer Marohasy exactly why we should be worried about ‘small’ changes’, or save Australian Senator Steve Fielding from looking too ignorant when he announces to the Government that he is ‘unconvinced about climate change‘.

Could coral reefs close to seagrass be buffered from ocean acidification?

coral1Seagrass meadows have long been known to be highly productive habitats, and as a result producing oodles of oxygen in the midday sun. Anyone who’s ever snorkelled over a seagrass meadow on a sunny day will have seen seagrass leaves furiously bubbling away. This photosynthetic productivity can result in an increase in the pH of the water column (becoming less acidic). This is primarily because CO2 and, thus, its form when dissolved in seawater, carbonic acid, are withdrawn from the water as a substrate for photosynthesis. This results in the production of the bubbling O2. But what are the consequences of such a pH change?

Recent research by the Universities of Dar es Salaam, Tel Aviv and Stockholm published in the Marine Ecology Progress Series (volume 382) and conducted in tropical seagrass meadows of East Africa have investigated the impact of such pH changes.  Semasi et al. revealed that this change in pH can cause localised increases in the rates of calcification and growth of calcareous algae such as Hydrolithon sp., Mesophyllum sp., and Halimeda sp., hence seagrass buffers high acidity (low pH).

As has been debated by ClimateShifts previously, there is increasing evidence that oceans have become more acidic since the start of the industrial era. Recent predictions suggest that oceans could become much more acidic over the next 100 years as a result of increasing CO2 emissions. Current predictions suggest that this will result in (amongst other things) declining reef calcification rates.

Although this study by Semesi et al. shows the effects of seagrass upon algae, the questions on the lips of many reef conservationists will be whether such findings are cross transferable to the calcification of corals. These studies in Zanzibar were small scale, carried out in seagrass mesocosms, and currently only reflect small scale patterns. Whether seagrass productivity can result in larger spatial scale changes that could buffer pH changes on nearby reefs remains to be seen. Maybe the World should be looking at seagrass meadows with greater attention?

Biogeochemists Map Out Carbon Dioxide Emissions In The U.


I stumbled across this great mapping system of CO2 emmisions over at Science Daily. Whilst previous estimates of CO2 levels have been calculated per capita in the US, a new map called ‘Vulcan’ created by biogeochemists at Purdue University shows the top local and regional carbon dioxide producers in high resolution.

In the past, CO2 levels have been calculated based on population, putting the Northeast at the top of the list. Now, a new map called Vulcan reveals for the first time where the top carbon dioxide producers are in the country. The answer surprised Kevin Gurney, Ph.D., a biogeochemist at Purdue University in West Lafayette, Ind.

“There are a lot more emissions in the Southeast than we previously thought, and a lot of that is because it’s not necessarily associated with where people live directly, but actually where industry and activities are,” said Dr. Gurney.

The high-resolution map shows 100 times more detail than ever before and zooms in to show greenhouse gas sources right down to factories, power plants and even roadways. An animated version of Vulcan reveals huge amounts of greenhouse gas gets blown toward the North Atlantic region.

“We’ve never had a map with this much detail and accuracy that everyone can view online,” Dr. Gurney said. (Read more @ Science Daily)

The official website (“The Vulcan Project“) has an amazing Google Earth interface, where you can map the emissions from US power producers, residential and commercial CO2 emissions at 100km2 local scale resolution. Perhaps the most interesting contrast is the maps of residential CO2 emissions when comparing Republican vs Democrat districts. Given the difference in population density between the US and Australia, it’d be interesting to see someone scale this effort to a continental scale, allowing regional comparisons and perspectives on global carbon budgets.