Guest post by Mike Favetta

The goal of “Climate without Borders” (CwB) is to unite TV weather presenters from all over the world and bring scientific knowledge to a broader public. This, in turn, creates climate awareness and creates support for the urgent climate action needed. Although the name suggests a kind of connection with Doctors without Borders, members of Climate without Borders won’t be traveling to island nations about to be submerged, like Tuvalu, or areas sub and physically volunteering in the refugee efforts. Rather, Climate without Borders is a network of TV weathercasters around the world who aim to communicate the science, and impact of climate change, and give warnings to their local viewing populations. This makes the organization unique in the world. TV weathercasters are trusted sources of information, and they know the nuances of their audience’s cultures to make messages more understandable. Exploiting this relationship is an effective way of sharing climate information that people will listen to and comprehend.

The story of Climate without Borders

How did it all begin? There’s a saying in TV news; if it bleeds, it leads. When the weather is at its fiercest, TV weathercasters are often recruited to explain. They’re held as bastions of scientific knowledge, even having to research obscure phenomenon that they might not be entirely familiar with. As global extreme weather events became more of a local news matter, TV meteorologists began to contact one another with questions about weather events specific to their region. Over the years, those messages developed into a private network in which weather presenters share information about climate and weather events, even offering new and unique perspectives to various noteworthy events, or to comment on published climate assessments.

When the Paris Agreement was signed, Mr Fabius who chaired the whole COP meeting stated that everyone could find its own piece in it. And Climate without Borders found its goal in Article 12, that states that all countries in the world should work on proper education, and invest in correct information, so that each and everyone becomes aware of the threat that comes with climate change, and the urgent climate action needed. The daily reach that weather presenters have nowadays is huge, through classic media such as TV and radio, and their socials. But being on the barricades of the changing weather patterns, doesn’t mean that all weather presenters are well educated and know how to answer on questions about sustainable mobility, agriculture, food patterns, etc.

Weather presenters reach many and are good communicators

For a large part of the population, the best phrase to instantly lose many people’s attention is “climate assessment” – How boring! Yet, it becomes the weather presenter’s job to make it interesting and relatable, possibly to someone’s wallet. If the talk of the town is how expensive a particular produce is at the market, which is directly due to extreme weather that damaged the crops, that would be time for the weather presenter to offer the explanation, relating to climate science. If a recent drought is causing a popular local harvest festival to be canceled, that would similarly get the viewer’s attention.

Climate experts are very smart people and most perform fantastic technical research. They are a critical part of furthering climate science. A common skill that could be improved, however, is proper communication to connect with their audiences, especially across various cultures. Similarly, journalists are excellent at telling a compelling story in print or on screen that instantly connects with their local audience, even with just one headline. Most of those journalists, though, lack the science background to turn the complex technical information into a clear and digestible message. This is where Climate without Borders comes in. We are the face of the Science. I am proud to be a founding member of the organization, someone who communicates the climate message in a clear and consistent manner by understanding my audience through and through.

While the situation in Tuvalu may be grave, the rest of us on the other side of the world don’t think about it often. But when a rapidly intensifying storm, supercharged by climate change, hits a major metropolitan area nearby to our hometown, we become obsessed with finding out the why or how. In this day and age, curious minds turn to social, asking their local TV weathercaster to explain what happened. Thanks to technology, the dynamic of TV weather presentations are changing. Instead of turning on the TV screen to wait for the curated weather forecast, more and more people are turning to their phone screens to get a customized weather report. But try to ask your digital assistant if climate change is responsible for the record flooding rains in tomorrow’s forecast, and there’s radio silence.

Climate without Borders activities

Climate without Borders’ goal is to expand our network so more countries are represented by their TV weathercasters. Additionally, Climate without Borders has started a school initiatives, which are an important way to get young students involved, so they can understand how the weather works, and how the changing climate can be felt in their own schoolyard. The Weatherbox campaign, for example, uses a Raspberry Pi board that students can program and connect to weather observing instruments to share the data with other schools and organizations around the world. This citizen science project will be launched in Belgium, supported by the local weather presenter, and from there it will be rolled out to other weather presenters, in more countries. Gathering data is key in this project, so to make better weather predictions and save people’s lives (adaptation), but also education so that climate actions can have a broader support from society (mitigation).

Help promote Climate without Borders

One way you can help our organization succeed is by voting for Climate without Borders in CCMC’s contest page here.
Climate without Borders has been selected as one of the contenders for the award “Best Climate Solution” in the category Education & Media. If you also believe in the power of climate communication by weather presenters, you can support Climate without Borders in this contest. It is as easy as this:
1. Register at the website: http://bit.ly/2QSLn1l
2. Give as many stars as possible to Climate without Borders: http://bit.ly/CwoB-BestClimateSolution
3. Click on the ‘VOTE’ button and it’s done

Climate without Borders logo

Mr. Favetta has been an American Meteorological Society member since 2005 and a certified consulting meteorologist (CCM) since 2016, and works in Milan/Italy and New York.

Guest article by William Ruddiman

Fifteen years after publication of Ruddiman (2003), the early anthropogenic hypothesis is still debated, with relevant evidence from many disciplines continuing to emerge. Recent findings summarized here lend support to the claim that greenhouse-gas emissions from early agriculture (before 1850) were large enough to alter atmospheric composition and global climate substantially.

Marine isotopic stage (MIS) 19 is the closest orbital analog to the current MIS 1 interglaciation (Tzedakis et al., 2012), with similarly small changes in precession (εsinω) and nearly synchronous peaks in sin and obliquity (Fig. 1a, b). MIS 11 was once claimed to be the closest MIS 1 analog (for example, Broecker and Stocker, 2006), but that claim is now rejected because obliquity and precession peaks in MIS 11 were far offset.

Figure 1 Comparison of (a) obliquity and (b) precession (εsinω) trends during MIS19, (green), MIS11 (black) and MIS1 (red). Based on Tzedakis et al. (2012). (c) CO2 trends during MIS19 (black) and MIS1 (red). CO2 data for MIS 19 are from Dome C (Bereiter et al. 2015). CO2 data for MIS 1 are from Law Dome (MacFarling Meure et al. 2006) and Dome C (Monnin et al. 2001, 2004) for MIS1.

With MIS 11 eliminated as an analog, the focus is on MIS 19. The CO2 signals early in MIS 1 and MIS 19 (Fig. 1c) reached nearly identical peaks of 270 and 269 ppm, after which the MIS 1 value fell for 4000 years but then rose by 20 ppm to a late pre-industrial 280-285 ppm. In contrast, the MIS 19 CO2 trend continued downward for more than 10,000 years to 245-250 ppm by the time equivalent to the present day. This value is consistent with the 240-245 ppm level proposed in the early anthropogenic hypothesis for a natural Holocene world (with no human overprint). The 35-ppm difference between the two interglaciations is close to the 40-ppm Holocene anomaly inferred by Ruddiman (2003).

A GCM simulation of the MIS 19 time equivalent to today by Vavrus et al. (2018) indicates that the low CO2 values would have caused year-round snow cover (indicative of incipient glaciation) in the Canadian Archipelago and over Baffin Island (an area roughly the size of Greenland), as well as other Arctic regions (see also Ganopolski et al., 2014).

Ruddiman (2003) estimated pre-industrial carbon emissions of 300-320 Gt, based on a back-of-the-envelope compilation of the incomplete forest clearance histories then available (Table 1). [One Gt is one billion tons]. That estimate was for a while rejected as too high by a factor of 5 to 10 (Joos et al., 2004; Pongratz et al., 2008; Stocker et al., 2011. However, Kaplan et al. (2011) found that those estimates had been biased downward because they assumed much smaller early per-capita clearance than the large amounts shown by actual historical data. Those estimates also ignored areas that had been cleared and were not in active agricultural use, but had not yet reforested. Adjusting for these factors, Kaplan and colleagues estimated pre-industrial emissions of 343 GtC.

Erb et al. (2017) averaged 7 estimates of the amount of carbon that would currently be stored in Earth’s potential natural vegetation had there been no human activities (910 GtC) compared to the 460 GtC carbon actually stored there today. They attributed the difference of 450 GtC to cumulative vegetation removal by humans (mostly deforestation). With ~140 GtC of clearance having occurred during the industrial era, that left an estimated 310 GtC as the total removed and emitted to the atmosphere during pre-industrial time. In a similar analysis, Lorenz and Lal (2018) estimated pre-industrial carbon emissions of ‘up to’ 357 GtC.

Studies in other disciplines have begun adding direct ground-truth evidence about early clearance. Analyses of pollen in hundreds of European lake cores (Fyfe et al., 2014; Roberts et al, 2018) show that forest vegetation began to decrease after 6000 years ago and reached near-modern levels before the start of the industrial era (Fig. 2). In China, compilations of over 50,000 archaeological sites by Li et al. (2009) and Hosner et al. (2016) show major increases of farming settlements in previously forested areas beginning 7,000 years ago. These extensive compilations support the above estimates of large early anthropogenic clearance and C emissions.

Figure 2. Evidence of early forest clearance in Europe. (A) Locations of cores in the European pollen database. Cores used for pollen summary in B are shown in red (Fyfe et al., 2015). (B) Changes in forest, open, and semi-open (mixed forest and open) vegetation plotted as ‘pseudobiome’ sums.

As this wide-ranging multi-disciplinary evidence has emerged, some scientists continue to reject the early anthropogenic hypothesis. Most of the opposition is based on a geochemical index (δ13CO2) measured in CO2 contained in air bubbles trapped in ice cores. The δ13CO2 index shows the relative balance through time between the amount of 12C-rich terrestrial carbon from the land and 13C-neutral carbon from the ocean. The small 13C decrease in atmospheric CO2 during the last 7000 years has been interpreted as indicating minimal input of 12C-rich terrestrial carbon during that time (Broecker and Stocker, 2006; Elsig et al., 2009). In a July 20, 2018 Scienceonline.org post, Jeff Severinghaus estimated the early human contribution to the observed CO2 rise as “1 to 2 ppm at the most”, or just 5-10% of the recent estimates reviewed in Table 1.

Other scientists (Stocker et al., 2018; Ruddiman et al., 2016) have pointed out that the δ13CO2 index cannot be used to isolate the amount of deforestation carbon unless all significant carbon sources and sinks are well constrained. The compilation by Yu (2011) indicating that ~300 Gt of terrestrial (12C-rich) carbon were buried in boreal peats during the last 7000 years shows that this constraint had not been satisfied in previous studies. Burial of ~300 GtC in boreal peats requires a counter-balancing emission of more than 300 GtC of terrestrial carbon during the last 7000 years, and the discussion above summarizes evidence that pre-industrial deforestation can fill that deficit. Even now, however, carbon exchanges (whether sources or sinks) in non-peat permafrost areas and in river floodplains and deltas during the last 7000 years remain poorly known.

Scientists trying to make up their minds about this still-ongoing debate can now weigh wide-ranging multi-disciplinary evidence for large early forest clearance against reliance on the as-yet poorly constrained δ13CO2 index.

References

Bereiter, B., S. Eggleston, J. Schmitt, C. Nehrbass-Ahles, T. F. Stocker, et al. (2015), Revision of the EPICA Dome C CO2 record from 800 to 600 kyr before present, Geophys. Res. Lett., 42, 542–549.

Broecker, W. S. and T. L. Stocker (2006), The Holocene CO2 rise: Anthropogenic or natural? EOS Trans. Amer. Geophysical Union 87, 27.

Erb, K.-H., T. Kastner, C. Plutzar, C., A. L. S Bais, N. Carvalhai., et al. (2018), Unexpectedly large impact of forest management on global vegetation biomass. Nature 553, 73-76.

Elsig J., J. Schmitt, D. Leuenberger, R. Schneider, M. Eyer, et al. (2009), Stable isotope constraints on Holocene carbon cycle changes from an Antarctic ice core. Nature 461, 507-510.

Fyfe, R. M., J. Woodbridge, and N. Roberts (2015), From forest to farmland: pollen-inferred land cover changes across Europe using the pseudobiomization approach. Global Change Biology 20, 1197-1212.

Ganopolski, A., R. Winkelmann and H. J. Schellenhuber, (2014), Critical insolation-CO2 relation for diagnosing past and future glacial inception. Nature 529, 200-203.

Hosner, D., M. Wagner, P. E. Tarasov, X. Chen, and C. Leipe (2016), Spatiotemporal distribution patterns of archaeological sites in China during the Neolithic and Bronze Age: An overview. The Holocene 26, 1576-1583.

Joos F, Gerber S, Prentice IC, et al. (2004) Transient simulations of Holocene atmospheric carbon dioxide and terrestrial carbon since the last glacial maximum. Global Biogeochemical Cycles 18. DOI: 10.1029/2003GB002156.

Kaplan J. O, K. M. Krumhardt, E. C. Ellis, W. F. Ruddiman, C. Lemmen, et al. Goldewijk (2011), Holocene carbon emissions as a result of anthropogenic land cover change. The Holocene 21, 775-792.

Li, X., J. Dodson, J. Zhou, and X. Zhou (2008), Increases of population and expansion of rice agriculture in Asia, and anthropogenic methane emissions since 5000 BP. Quat. Int. 202, 41-50.

Lorenz, K. and R. Lal (2018), Agricultural land use and the global carbon cycle. In: Carbon sequestration in agricultural systems, p. 1-37.

MacFarling Meure, C., D. Etheridge, C. Trudinger, P. Steele, R. Langenfelds, et al. (2006), Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP. Geophys. Res. Lett., 33, L14810, doi:10.1029/2006GL026152.

Monnin E., A. Indermühle, A. Dällenbach, J. Flückinger, B. Stauffer, et al. (2001), Atmospheric CO¬¬2 concentrations over the Last Glacial Termination. Science, 291, 112-114.

Pongratz, J., C. Reick, T. Raddatz, and M. A. Claussen (2008), A reconstruction of global agricultural areas and land cover for the last millennium. Global Geochemical Cycles 22, GB3018m doi:10.1029/2008GLO36394.

Roberts N, R. M. Fyfe, J. Woodbridge, et al. (2018), Europe’s forests: A pollen-based synthesis for the last 11,000 years. Nature Scientific Reports. DOI: 10.1038/s41598-017-18646-7
Ruddiman, W. F. (2003), The anthropogenic greenhouse era began thousands of years ago. Climatic Change 61, 261-293.

Ruddiman, W. F., D. Q. Fuller, J. E Kutzbach, P. C. Tzedakis, J. O. Kaplan et al. (2016), Late Holocene climate: Natural or anthropogenic? Rev. of Geophys. 54, 93-118.

Stocker, B. D., K. Strassmann, and F. Joos (2011), Sensitivity of Holocene atmospheric CO2 and the modern carbon budget to early human land use: analyses with a process-base model. Biogeosciences 8, 69-88.

Stocker, B.D., Z. Yu, and F. Joos (2018), Constraining CO2 emissions from different Holocene land-use histories: does the carbon budget add up? PAGES 26, 6-7.

Tzedakis, P. C., J. E. T. Channell, D. A. Hodell, H. F. Kleiven, and L. K. Skinner (2012), Determining the length of the current interglacial. Nature Geoscience 5, 138-141.

Vavrus, S. J., F. He, J. E. Kutzbach, W. F. Ruddiman, and P. C. Tzedakis (2018), Glacial inception in marine isotope stage 19: An orbital analog for a
natural Holocene. Nature Scientific Reports 81, doi:10.1038/s41598-018-28419-5.

Responding to climate change is far more like a marathon than a sprint.

The IPCC 1.5ºC Special report (#SR15) has been released:

• The press release
• Frequently Asked Questions
• The Summary For Policy Makers (SPM)
• The full report

Thoughts

It’s well worth reading the SPM and FAQs before confidently pronouncing on the utility or impact of this report. The FAQs include the following questions:

1. FAQ 1.1: Why are we talking about 1.5°C?
2. FAQ 1.2: How close are we to 1.5°C?
3. FAQ 2.1: What kind of pathways limit warming to 1.5°C and are we on track?
4. FAQ 2.2: What do energy supply and demand have to do with limiting warming to 1.5°C?
5. FAQ 3.1: What are the impacts of 1.5°C and 2°C of warming?
6. FAQ 4.1: What transitions could enable limiting global warming to 1.5°C?
7. FAQ 4.2: What are Carbon Dioxide Removal and negative emissions?
8. FAQ 4.3: Why is adaptation important in a 1.5°C warmer world?
9. FAQ 5.1: What are the connections between sustainable development and limiting global warming to 1.5°C?
10. FAQ 5.2: What are the pathways to achieving poverty reduction and reducing inequalities while reaching the 1.5°C world?

First thing to remember is that this special report was commissioned from the UNFCCC on the back of the Paris Accord (which is not the process for main IPCC reports). Secondly, the IPCC is constrained to only assess published literature or otherwise publically available data. This means that if no groups have studied a question, there isn’t much to assess. Sometimes the gaps are apparent even in the scoping of the reports which can encourage people to focus on them at an early stage and have publications ready in time for the final report, but one of the main impacts of any of these reports is to influence research directions going forward.

What does 1.5ºC mean?

The SR15 has defined 1.5ºC as the warming from the period 1850-1900. This is 2.7ºF and about 1/3rd of an ice age unit (the amount of warming from the depths of the last ice age 20,000 years ago to the mid-19th Century).

This baseline is not really “pre-industrial”, and there have been some interesting discussions on what that phrase might be usefully defined as (Hawkins et al ,2017; Mann et al, 2017), but this baseline is the easiest to adopt since estimates of climate impacts are being based on climate models from CMIP5 which effectively use that same baseline. The timing of projected impacts is a little sensitive to definitional issues with the “global mean” temperature, and whether the instrumental record is biased with respect to changes in the mean – particularly in the earlier part of the record when the data is relatively sparse.

At current rates, we’ll hit 1.5ºC on a decadal-average basis by ~2040. The first year above 1.5ºC will occur substantially earlier, likely associated with a big El Niño event in the late 2020s/early 2030s.

Can we avoid going through 1.5ºC?

IPCC has to use a few circumlocutions to avoid giving a direct answer to this question (for reasonable and understandable reasons). I’m not quite so constrained…

There are many issues related to the feasibility question of which physical climate-related issues are only one. The basic issue is that the effort to reduce emissions sufficiently to never get past 1.5ºC would require a global effort to decarbonize starting immediately that would dwarf current efforts or pledges. This seems unlikely (IMO).

There are a few ‘get-out-of-jail’ cards that are considered. First, we can overshoot 1.5ºC, and then come back down after heroic efforts to reduce CO2 levels in the atmosphere though so-called ‘negative emissions’. This makes the immediate task less daunting, but at the expense of relying on global scale efforts with carbon sequestration, or BECCS, or direct air capture, which are extremely speculative. Second, we could start direct geo-engineering efforts to reduce temperatures and (most optimistically) buy time for carbon emissions to come down a little more slowly. Both of these scenarios come with dramatic and underexplored geo-political consequences (are there any stable governance regimes for geo-engineering? is there sufficient land for large scale BECCS?), as well as substantial moral hazard.

So my answer is… no.

I get that there is reluctance to say this publically – it sounds as if one is complicit in the impacts that will occur above 1.5ºC, but it seems to me that tractable challenges are more motivating than impossible (or extremely unfeasible) ones – I would be happy to be proven wrong on this though.

The utility of the SR15 report?

Even if you think that working on responses to impacts that are almost certainly going to be smaller than we are actually going to see, there are some useful aspects of this report. The basic fact is that moving beyond the small efforts that have been made so far implies transitions that are effectively the same whether we hope to stabilise at 1.5ºC, 2ºC or even 3ºC – only the rate at which they are implemented differs.

This is because near-term reductions in carbon emissions by ~70% are required to even stabilize CO2, and to stabilize temperature, even further (net) reductions are required. And worse still to stabilize sea level, eventual temperature drops would be required.

Efforts on these scales are not easy, and will need to be sustained over many decades and much of the work discussed in this report will be central to that. Nonetheless, this will be a marathon effort. It is thus perhaps worth paraphrasing Eliud Kipchoge, the recent winner of the Berlin marathon:

The best time to start [reducing emissions] was 25 years ago. The second best time is today.

References

1. 
   E. Hawkins, P. Ortega, E. Suckling, A. Schurer, G. Hegerl, P. Jones, M. Joshi, T.J. Osborn, V. Masson-Delmotte, J. Mignot, P. Thorne, and G.J. van Oldenborgh, “Estimating Changes in Global Temperature since the Preindustrial Period”, Bulletin of the American Meteorological Society, vol. 98, pp. 1841-1856, 2017. http://dx.doi.org/10.1175/BAMS-D-16-0007.1

2. 
   A.P. Schurer, M.E. Mann, E. Hawkins, S.F.B. Tett, and G.C. Hegerl, “Importance of the pre-industrial baseline for likelihood of exceeding Paris goals”, Nature Climate Change, vol. 7, pp. 563-567, 2017. http://dx.doi.org/10.1038/nclimate3345