Home

Crowdfunding Countercurrents

CC Archive

Submission Policy

Join News Letter

Defend Indian Constitution

#SaveVizhinjam

CounterSolutions

CounterImages

CounterVideos

CC Youtube Channel

India Burning

Mumbai Terror

Iraq

Peak Oil

Globalisation

Localism

Climate Change

US Imperialism

Palestine

Communalism

Dalit

Humanrights

Economy

India-pakistan

Kashmir

Book Review

Gujarat Pogrom

Kandhamal Violence

Arts/Culture

Archives

About Us

Popularise CC

Disclaimer

Fair Use Notice

Contact Us

Subscribe To Our
News Letter

Name


E-mail:



Search Our Archive



Our Site

Web

 

 

 

 

Regional Climate Change And National Responsibilities

By James Hansen & Makiko Sato

03 March, 2016
Iopscience.iop.org

Global warming over the past several decades is now large enough that regional climate change is emerging above the noise of natural variability, especially in the summer at middle latitudes and year-round at low latitudes. Despite the small magnitude of warming relative to weather fluctuations, effects of the warming already have notable social and economic impacts. Global warming of 2 °C relative to preindustrial would shift the 'bell curve' defining temperature anomalies a factor of three larger than observed changes since the middle of the 20th century, with highly deleterious consequences. There is striking incongruity between the global distribution of nations principally responsible for fossil fuel CO2 emissions, known to be the main cause of climate change, and the regions suffering the greatest consequences from the warming, a fact with substantial implications for global energy and climate policies.

 

Global warming since preindustrial time, barely 1 °C, is small compared to weather fluctuations, yet seasonal mean temperature anomalies in most land areas are now large enough to noticeably load the 'climate dice'. The public should notice that climate is changing, because warming of recent decades has shifted the 'bell curve' describing seasonal mean local temperature anomalies over the summer hemisphere by about one standard deviation (Hansen et al 2012). What were once unusually warm conditions now occur more frequently, and the most extreme warm events now are more extreme than before. However, the magnitude of change varies around the globe.

Here we update the hemispheric analysis and illustrate regional changes, each shown by the bell curve for the frequency of occurrence of a given seasonal mean temperature anomaly relative to a climatological (base) period, 1951–1980, which largely preceded the rapid global warming trend of the past four decades. Results differ little if we use a longer base period, 1931–1980 (Hansen et al 2013a). The rationale for the bell curve presentation is that it provides a simple clear indication of significant change.

We find that recent warming during summer in arid and semi-arid subtropical regions such as the Mediterranean and Middle East is at least two standard deviations, far exceeding natural variability. Warming is similarly large in all seasons in the tropics. Large low latitude warming has been reported earlier by Diffenbaugh and Scherer (2011) and Mahlstein et al (2011, 2012). Added to natural subtropical aridity and high temperatures at low latitudes, this large warming contributes to drought intensification in the subtropics and makes living and working conditions more difficult in low latitudes. We will note works suggesting that higher temperatures affect economic production, contribute to human health problems, and tend to increase human conflict, perhaps increasing pressures for migration, but mainly we point to the need for research on these topics. In contrast, we can be quantitative in updating national responsibilities for fossil fuel CO2 emissions, which are known to be the principal cause of global warming.

In updating results for Northern and Southern Hemisphere land areas (figure 1) we break the 66-year period 1950–2015 into six 11 year periods, so the periods have equal statistical significance. For clarity not all 11 year periods are included in our figures. Warming is larger in winter than in summer (Hansen et al 2010, IPCC 2013), but year-to-year temperature variability is much larger in winter (see global maps of interannual standard deviation of seasonal mean temperature in figure 2 of Hansen et al 2012). Thus the shift of the 'bell curve' (distribution of temperature anomalies in units of standard deviation) is larger in summer than in winter (figure 1), implying that climate change is easier to detect in summer than in winter. However, seasonal variation of the bell curve shift (figure 1) is small in the Southern Hemisphere, because a large fraction of Southern Hemisphere land is at low latitudes where seasonal change is small and because the dominance of ocean area in the Southern Hemisphere moderates seasonal change.

Figure 1. Frequency of occurrence of local temperature anomalies (relative to 1951–1980 mean) divided by local standard deviation (horizontal axis) for land areas shown on map. Area under each curve is unity. Numbers above the maps are percent of the globe covered by the selected region. 'Shift' and 'width' refer to the dashed curve fit to 2005–2015 data and are relative to the 1951–1980 base period (see text).

We calculate the 'shift' and the 'width' of the bell curve for each 11 year period relative to the 1951–1980 base period by finding the μ and σ yielding best least-mean-square fit of the data to

The 'shift' for any 11 year period is the difference between the seasonal mean temperature during that 11 year period and the climatology period (1951–1980) in units of the standard deviation of seasonal mean temperature during 1951–1980. The 'width' is the ratio of the standard deviation in the 11 year period and in 1951–1980. The shift and width for the 2005–2015 bell curves are given in the upper right hand corner of the graphs.

Shift of seasonal mean temperature in units of standard deviation usefully characterizes local climate change, as it measures change relative to the range of conditions that humans and other species at that locale are adapted to. Global temperature is now probably slightly above the prior Holocene maximum (Hansen et al 2013b), and despite regional Holocene variability (Mayewski et al 2004), in most regions further warming will take temperature to levels not experienced since at least the prior interglacial, more than 100 000 years ago. A question of interest is thus how large the temperature change is relative to the historic variability at that location.

The bell curve width increases with global warming and the curve tends to become slightly asymmetric with an increasingly long tail on the 'hot' side. The bell curve would become a near-symmetric normal distribution if we defined anomalies relative to the most recent decades rather than 1951–1980 (Rhines and Huybers 2013, Hansen et al 2013c), but it is appropriate to define anomalies relative to the time before the sharp warming trend for reasons given above.

Our analysis is of seasonal mean temperature, but emergence from noise of seasonal and daily extremes are tightly coupled, with seasonal change preceding daily change (King et al 2015). Our analysis (figure 1) agrees with the conclusion of Seneviratne et al (2014) and Sillmann et al (2014) that the trend toward increasingly hot extremes has continued in the most recent decade, despite evidence of a slowdown or hiatus in global surface warming (Meehl et al 2011, IPCC 2013). Existence of a global warming hiatus has also been questioned (Karl et al 2015).

Now we examine the bell curve changes in various geographical regions (figure 2). The curves become 'noiser' as the regions becomes smaller, yet the effect of warming is easily discernable.


Figure 2. Shifting bell curves that define the frequency of local temperature anomalies relative to the 1951–1980 base period for four regions, with definitions and nomenclature as in figure 1.

The summer bell curves for the United States and (North and Central) Europe are shifted more than one standard deviation (1σ), while the shift in the winter is only about half of a standard deviation. The shift in summer is enough to increase the frequency of summers warmer than +2σ from less than 1% to greater than 10%. The perceptive public may be able to notice this degree of change, but there is a geographical variation of the signal within the United States, as we will discuss. The bell curve shift in winter is too small to be easily noticed. The changes in Europe are only slightly larger than those in the United States.

The bell curve shifts are larger in China and India, being about one and one-half standard deviations in summer and one standard deviation in winter. The area that we employed for the India region includes the neighboring countries of Pakistan, Bangladesh and Sri Lanka, thus reducing the noise by achieving an area of about 0.7% of the globe. These bell curve shifts should be noticeable and have practical effects, which we will discuss.

This climate change signal, measured in units of the normal variability, becomes even stronger at lower latitudes, as we move well into the subtropics and tropics (figure 3). The summer bell curve shift is +2.4σ in the Mediterranean and Middle East region, which means that almost every summer is warmer than average conditions in 1951–1980 and most summers are at least +2σ relative to the climate of 50 years earlier. Warming in the Sahara and Sahel is similar to that in the Mediterraen and Middle East, although noisier because of more limited data.


Figure 3. Shifting bell curves that define the frequency of local temperature anomalies relative to the 1951–1980 base period for four regions, with definitions and nomenclature as in figure 1.

South-East Asia and the African Rainforest, moist tropical regions, have bell curve shifts toward warmer temperatures exceeding +2σ in June–July–August, i.e., a warming signal as large as the shift in the subtropical dry belt and desert. Moreover the shift in these tropical regions is as large or almost as large in the other seasons, as shown for December–January–February (figure 3).

We do not illustrate the results for the three individual regions in the Southern Hemisphere (Australia, South America and the southern part of Africa) because we find the bell curves and their shifts for all three regions are very similar to those for the three areas together. The results for these areas are thus adequately described by the lower half of figure 1.

Global warming that leads to the large shift of the regional bell curves has been definitively associated with increasing atmospheric greenhouse gases (GHGs), principally CO2 from fossil fuel burning (e.g., IPCC 2013, Hansen et al 2013b). Although global warming is only approaching 1 °C, the regional bell curves reveal that the warming signal has emphatically emerged on regional scales. The conclusion that the signal should emerge first at low latitudes in summer was reached already by Diffenbaugh and Scherer (2011) and Mahlstein et al (2011, 2012).

Regional bell curves, in addition to being 'noisy' because of small areas, are affected more by dynamical phenomena such as the El Niño/Southern Oscillation (Rasmusson and Wallace 1983) and North Atlantic Oscillation (Hurrell 1995). Thus decade-to-decade shifting of the bell curve is more irregular for regions than for a hemisphere. For this reason we emphasize total change from the base period to the most recent decade, minimizing the effect of regional dynamics.

Insight is provided by global maps of the temperature change that gives rise to the shifting bell curves. The temperature data that we employ is NASA/GISS surface temperature analysis (Hansen et al 2010) over land areas at 250 km resolution (figure 4). This analysis is based on the latest GHCN (Global Historical Climatology Network) data obtained from NOAA, GHCN version 3.3.0. We note that GHCN land data have been very stable in sucessive updates, and thus the updates do not alter our prior analyses. Sea surface temperature (SST) data have undergone greater changes in recent years, but SST data are not employed in our present study.


Figure 4. Surface air temperature anomalies in 2005–2015 relative to base period 1951–1980.

Large warming in 2005–2015 exists not only in the Mediterranean, Middle-East, Sahara region but also in the Gobi Desert and Southwest United States. Amplified warming in desert regions (Cook and Vizy 2015) and a tendency for increasing heatwaves and strong droughts to coincide (Mazdiyasni and AghaKouchak 2015) are expected consequences of increased global warming. Generally, as global warming increases, climatologically wet regions tend to get wetter and dry regions get hotter and drier (figure 2.33 in IPCC 2013). Polar amplification of surface warming is also apparent (figure 4), but that warming occurs where interannual climate variabitily is very large, so the signal-to-noise ratio and bell curve shifts are smaller at high latitudes.

Next, based on available peer-reviewed studies, we briefly review practical impacts expected to result from the shifting temperature bell curves discussed above.

Livlihoods are affected by higher temperature and associated absolute humidity, especially at latitudes with conditions already near the tolerance limit for outdoor work, as more than half of non-household labor-hours occur outdoors (ILO 2013, IPCC 2014, section 13.2). Developing countries in the tropics are affected disproportionately (Dunne et al 2013, Kjellstrom et al 2013, Lundgren et al 2013), but workers in places such as southern United States and eastern China are also affected by increasing temperature and absolute humidity (Luginbuhl et al 2008).

Human health is affected by higher temperature via impacts on heat waves, drought, fires, floods and storms, and indirectly by ecological disruptions brought on by climate change including shifting patterns of disease (Lafferty 2009, Altizer et al 2013, IPCC 2014, ch 11). Vector-borne diseases, usually involving infections transmitted by blood-sucking mosquitoes or ticks, are sensitive to changing climate (IPCC 2014, section 11.5). Other factors will affect future disease incidence, but it can be concluded that higher temperatures allow the spread of some disease vectors to greater altitudes and higher latitudes (IPCC 2014, section 11.5).

National responsibilities for global warming can be assigned under the premise that fossil fuel CO2 emissions are the primary issue for long-term warming. Deforestation and agricultural activities also contribute to atmospheric CO2, but potential restoration of carbon into the soil and biosphere has comparable magnitude; indeed, assumption of such restoration via improved agricultural and forestry practices, including reforestation of lands that are of marginal value for crops, seems required if climate is to be stabilized at a level close to the Holocene temperature range (Hansen et al 2008, National Research Council 2015). In contrast, carbon released in fossil fuel burning will not be naturally removed from the climate system for millennia (Archer 2005, IPCC 2013, ch 6). CH4, N2O, O3 and other gases also contribute to human-made climate change, but CO2 contributes about 80% of the increase of GHG climate forcing in the past two decades (see figure 5 of Hansen et al 2013d) and much of the increase of the other 20% is related to fossil fuel mining or fossil fuel use.

Current fossil fuel CO2 emissions are shown in figure 5(a). China is the largest source of current emissions, with the United States second and India a rapidly growing third. However, climate change is accurately proportional to cumulative emissions (Hansen et al 2007, Matthews et al 2009), shown in figure 5(b). The United States and Europe, including their portions of air and ship emissions, are each responsible for more than one-quarter of the climate change, China about 10% and India about 3%. Consumption-based accounting for emissions (Peters 2008) increases this disparity between developed and developing country emissions.


Figure 5. Fossil fuel CO2 emissions by source in 2014 and cumulative 1751–2014. Results are an update of figure 10 of Hansen et al (2013b) using data of Boden et al (2015) and BP (2015).

Per capita fossil fuel emissions (figure 6(a)) and cumulative emissions (figure 6(b)) provide a useful perspective on emission responsibilities. Despite China's high current emissions, on a per capita basis they remain lower than many western nations, and slightly larger than the global average. Cumulative per capita emissions by China are an order of magnitude smaller than US emissions, and India's cumulative per capita emissions are even smaller.

 


Figure 6. Per capita fossil fuel CO2 emissions in 2014 and cumulative. Data sources as in figure 5. Results for additional individual nations are available at www.columbia.edu/~mhs119/CO2Emissions/.

Results similar to figures 5 and 6 have been reported many places. Our figures, available at www.columbia.edu/~mhs119/CO2Emissions/, are normally updated annually using indicated sources. Uncertainties in Chinese emissions include probable overestimate of coal emission factors (Liu et al 2015) and possible underreeporting of coal use (Buckley 2015).

There is striking incongruity between locations of largest climate change and fossil fuel emission sources, as noted by Diffenbaugh and Scherer (2011) and Mahlstein et al (2011, 2012). Largest bell curve shift is in tropical rainforest, South-East Asia, the Sahara and Sahel (figure 3). Largest temperature shift, in units of its natural variability, does not necessarily imply largest impact on local inhabitants. However, the fact that largest changes occur in places already near the limits of human heat tolerance suggests that added heat may be a problem. Fossil fuel emissions from nations in these areas are very small (Boden et al 2015). The only nation in these regions with current emissions as large as the global mean (figure 6(a)) is Malyasia, with current per capita emissions of about 2 tonsC/year/person. However, the cumulative emissions from these nations are all very small in comparison with developed nations, with African emissions even less than that of India (figure 6(b)). In other words, the nations experiencing the largest change of prior normal climate bear negligible responsibility for causing the climate change.

An equally large climate shift is occurring in the Mediterranean + Middle East region. The large shift is confined to the lengthening warm season, when temperatures are already near the limit of human heat tolerance. At minimum the added heat makes life more difficult in the summer and reduces productivity; it also intensifies drought conditions such as those in Syria in recent years, if not being a principal cause of the drought (Kelley et al 2015). As for emission responsibility, unlike most of Africa and South-East Asia, per capita emissions from the Middle East are among the largest in the world (figure 6(a)) and the fastest growing as the price of fossil fuels is kept low in many countries via government subsidies. Qatar, Kuwait, Oman, United Arab Emirates and Saudi Arabia have per capita emissions ranging from 12 to 5 tons of carbon per person per year, all greater than per capita emissions in the United States (figure 6(a)). Cumulative emissions per capita by Middle Eastern nations are not as large as in countries that developed earlier, but they are larger than the global mean (figure 6(b)).

The bell curve shifts in 2005–2015 are only about one-third of the shift that will occur with 2 °C global warming. (Although warming of land areas in 2005–2015 is ~0.8 °C, figure 4, global mean warming is only ~0.6 °C relative to 1951–80; 1951–80 is ~0.3 °C warmer than pre-industrial, Hansen et al (2010), so 2 °C warming above pre-industrial implies 1.7 °C relative to 1951–1980.) Given the approximate linearity between mean temperature increase and bell curve shift, 2 °C global warming would yield a shift of about six standard deviations during summer in the Mediteranean, Middle East, Sahara and Sahel regions and a similar shift in all seasons in the African Rainforest and Southeast Asia (figure 3).

Implications of these regional climate shifts are manifold. We note several consequences, focusing on their geographically uneven impact, especially the difference between developing countries at low latitudes and more developed northern nations. The examples and not a review of these burgeoning research areas, but they are sufficient to introduce discussion of relevance of these regional changes to the issue of dangerous human-made climate change.

Hsiang et al (2013) assemble the results of 60 quantitative studies of the relation between climate change and human conflict spanning the last 10 000 years and all major world regions. They find that interpersonal violence increases by 4% and intergroup conflict by 14% for each standard deviation change in temperature toward warmer temperatures. Such findings do not constitute natural laws, but they provide a useful empirical estimate of impacts that can be used for at least a limited range of temperature increase. Increases we infer of 2–6 standard deviations with 2 °C global warming imply significant effects in all regions, but with larger effects at lower latitudes. Conflicts in turn tend to result in migrations with effects on both displaced and host populations (McMichael et al 2012).

Temperature rise itself imposes a strong disproportionately large effect on low latitude countries. Pal and Eltahir (2016) note that business-as-usual fossil fuel emissions result in some regions in the Middle East becoming practically uninhabitable by the end of this century as the wet bulb temperature approaches the level at which the human body is unable to cool itself under even well-ventilated outdoor conditions (Sherwood and Huber 2010). Today's global temperature distribution has notable nonlinear effect on economic productivity (Burke et al 2015). Middle latitude countries have near-optimum temperature and limited impact from projected temperature change, but, in contrast, warmer countries, such as Indonesia, India and Nigeria are on a steep slope with rapidly declining productivity as temperature rises (figure 2, Burke et al 2015).

These regional consequences of warming are accompanied by a threat that sea level rise poses to global coastlines, thus jointly creating a need for prompt strong actions to avoid tragic results. Earth's history suggests that warming of even 1 °C above pre-industrial levels could eventually lead to 6–9 m sea level rise (Dutton et al 2015). IPCC (2013) estimates that about 1 m or less sea level rise would occur by 2100, but Hansen et al (2015) argue that amplifying feedbacks make a highly nonlinear response likely with potential for several meters of sea level rise this century and recent ice sheet models explore mechanisms that may contribute to rapid ice sheet collapse (Pollard et al 2015). If the ocean continues to accumulate heat and increase melting of marine-terminating ice shelves of Antarctica and Greenland, a point may be reached at which it is impossible to avoid large scale ice sheet disintegration. Given that a majority of large global cities are located on coastlines, sea level rise would add another source of migration pressure.

The United Nations 1992 Framework Convention on Climate Change (UNFCCC 1992) stated its objective as '...stabilization of GHG concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system'. The 15th Conference of the Parties (Copenhagen Accord 2009) changed the focus to a goal to '...reduce global emissions so as to hold the increase of global temperature below 2 °C...', and the 21st Conference of the parties added an aspirational goal of below 1.5 °C (Davenport 2015). However, we suggest that the UNFCCC (1992) objective to stabilize GHG concentrations is fundamental and starkly informs policy requirements.

Atmospheric CO2 amount, in particular, is a great challenge in limiting GHG concentration. Earth's paleoclimate history, especially the sensitivity of sea level to global temperature (Dutton et al 2015), and knowledge of Earth's carbon cycle (Archer 2005, IPCC 2013, ch 6 ) provide a strong constraint, which Hansen et al (2008) use to infer that CO2 must be restored to a level no higher than ~350 ppm, with restoration prompt enough to avoid practically irreversible ocean warming and ice sheet disintegration. This estimate for the CO2 ceiling was affirmed by accurate measurements of Earth's present energy imbalance (Hansen et al 2011, von Schuckmann et al 2016).

Restoration of CO2 to a level at or below 350 ppm within a century, even with optimistic assumptions about restoration of biospheric and soil carbon, would require reductions of fossil fuel emissions by 5%–7% per year if reductions are started promptly (Hansen et al 2013b). Failure to achieve such reduction will result in continued long-term energy imbalance with Earth's surface and ocean continuing to warm, growing regional climate impacts, accelerating ice sheet disintegration, and more rapidly rising sea level. As evidence of the situation and consequences grows, there may be increasing calls for climate 'geo-engineering' (Royal Society 2009) with unknown consequences (Sillmann et al 2015).

Country-by-country goals, the approach of the 21st Conference of the Parties (Davenport 2015), will not lead to planetary energy balance and climate stabilitzation if fossil fuels are the cheapest energy. It is necessary to include 'external' costs to society in the fossil fuel price, especially the costs of climate change and air and water pollution (Ackerman and Stanton 2012), so that carbon-free energies and energy efficiency can supplant fossil fuels more rapidly. Such inclusive pricing of fossil fuels makes economies more efficient and reduces net economic hardships, if the carbon fee, collected from fossil fuel companies at domestic mines and ports of entry, rises gradually and if the funds are distributed uniformly to the public (Hansen 2015).

A carbon fee can be initiated by a few major economic powers and spread to most nations via border duties on fossil-fuel-derived products from non-participating nations and fee rebates to domestic manufacturers for goods shipped to non-participating nations (Hsu 2011). Issues raised by 'coercive cooperation' implicit in border adjustments (Bohringer et al 2012) will be subdued, once the severity and urgency of the climate threat is widely appreciated, by realization that fossil fuels cannot be phased out if some countries are allowed to export products made with untaxed fossil fuels. Developing countries have rights, recognized in the concept of common but differentiated responsibilities, and leverage to achieve economic assistance, which should be tied to the improved agricultural and forestry practices needed to limit trace gas emissions and store more carbon in the soil and biosphere. Finally, international cooperation in generating more affordable carbon-free energies is needed, or economic development in many nations will continue to be based on fossil fuels, despite pollution and climate impacts.

Acknowlegments

We thank two anonymous referees for reviews that markedly improved our paper. We greatly appreciate support of the Durst family, the Grantham Foundation for Protection of the Environment, Jim and Krisann Miller, Gerry Lenfest, the Flora Family Foundation, Alexander Totic and Hugh Perrine for supporting our Climate Science, Awareness and Solutions program.

References

Ackerman F and Stanton E A 2012 Climate risks and carbon prices: revising the social cost of carbon Econ. E-J. 6 1–25
CrossRef

Altizer S, Ostfeld R S, Johnson P T J, Kutz S and Harvell C D 2013 Climate change and infectious diseases: from evidence to a predictive framework Science 341 514–9
CrossRef

Archer D 2005 Fate of fossil fuel CO2 in geologic time J. Geophys. Res. 110 C09S05
CrossRef

Boden T A, Marland G and Andres R J 2015 Global, Regional, and National Fossil-Fuel CO (Oak Ridge, TN: Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory)
CrossRef

Bohringer C, Balistreri E J and Rutherford T F 2012 The role of border carbon adjustment in unilateral climate policy: overview of an energy modeling forum study (EMF 29) Energy Econ. 34 S97–110
CrossRef

BP 2015 BP Statistical Review of World Energy 2015 (http://bp.com/en/global/corporate/about-bp/energy-economics/statistical-review-of-world-energy.html)

Buckley C 2015 China burns much more coal than reported, complicating climate talks New York Times 3 November (www.nytimes.com/2015/11/04/world/asia/china-burns-much-more-coal-than-reported-complicating-climate-talks.html?_r=0)

Burke M, Hsiang S M and Miguel E 2015 Global nonlinear effect of temperature on economic production Nature 527 235–9
CrossRef

Cook K H and Vizy E K 2015 Detection and analysis of an amplified warming of the Sahara J. Clim. 28 6560–80
CrossRef

Copenhagen Accord 2009 United Nations Framework Convention on Climate Change, Draft Decision—/CP.15 FCCC/CP/2009/L (http://unfccc.int/meetings/copenhagen_dec_2009/meeting/6295.php)

Davenport C 2015 Nations Approve Landmark Climate Accord in Paris New York Times 12 December (www.nytimes.com/2015/12/13/world/europe/climate-change-accord-paris.html)

Diffenbaugh N S and Scherer M 2011 Observational and model evidence of global emergence of permanent, unprecedented heat in the 20th and 21st centuries Clim. Change 107 615–24
CrossRef

Dunne J P, Stouffer R J and John J G 2013 Reductions in labour capacity from heat stress under climate warming Nat. Clim. Change 3 563–6
CrossRef

Dutton A, Carlson A E, Long A J, Milne G A, Clark P U, DeConto R, Horton B P, Rahmstorf S and Raymo M E 2015 Sea-level rise due to polar ice-sheet mass loss during past warm periods Science 349 153–63
CrossRef

Hansen J et al 2007 Dangerous human-made interference with climate: a GISS modelE study Atmos. Chem. Phys. 7 2287–312
CrossRef

Hansen J, Ruedy R, Sato M and Lo K 2010 Global surface temperature change Rev. Geophys. 48 RG4004
CrossRef

Hansen J, Sato M, Kharecha P, Beerling D, Berner R, Masson-Delmotte V, Pagani M, Raymo M, Royer D L and Zachos J C 2008 Target atmospheric CO2: where should humanity aim? Open Atmos. Sci. J. 2 217–31
CrossRef

Hansen J, Sato M, Kharecha P and von Schuckmann K 2011 Earth’s energy imbalance and implications Atmos. Chem. Phys. 11 13421–49
CrossRef

Hansen J, Sato M and Ruedy R 2012 Perception of climate change Proc. Natl Acad. Sci. USA 109 14726–7
CrossRef

Hansen J, Sato M and Ruedy R 2013a Reply to Stone et al: Human-made role in local temperature extremes Proc. Natl Acad. Sci. USA 110 E1544
CrossRef

Hansen J et al 2013b Assessing ‘dangerous climate change’: Required reduction of carbon emissions to protect young people, future generations and nature PloS One 8 e81648
CrossRef

Hansen J, Sato M and Ruedy R 2013c Reply to Rhines and Huybers: Changes in the frequency of extreme summer heat Proc. Natl Acad. Sci. 110 E547–8
CrossRef

Hansen J, Kharecha P and Sato M 2013d Climate forcing growth rates: doubling down on our Faustian bargain Environ. Res. Lett. 8 011006
IOPscience

Hansen J E 2015 Environment and development challenges: the imperative of a carbon fee and dividend The Oxford Handbook of the Macroeconomics of Global Warming ed L Bernard and W Semmler (Oxford: Oxford University Press)
CrossRef

Hansen J et al 2016 Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming is dangerous (arXiv:1602.01393)

Hsiang S M, Burke M and Miguel E 2013 Quantifying the influence of climate on human conflict Science 341 1235367
CrossRef

Hsu S L 2011 The Case for a Carbon Tax (Washington, DC: Island Press) p 233

Hurrell J W 1995 Decadal trends in the North Atlantic Oscillation: regional temperatures and precipitation Science 269 676–9
CrossRef

International Labour Organization (ILO) 2013 Global Employment Trends 2013: Recovering from a Second Jobs Dip. (Geneva Switzerland: International Labour Organization) p 140

IPCC (Intergovernmental Panel on Climate Change) 2013 Climate Change 2013 ed T Stocker et al (Cambridge: Cambridge University Press) p 1535

IPCC (Intergovernmental Panel on Climate Change) 2014 Climate Change 2014 ed C B Field et al (Cambridge: Cambridge University Press) p 1132

Karl T R, Arguez A, Huang B, Lawrimore J H, McMahon J R, Menne M J, Peterson T C, Vose R S and Zhang H M 2015 Possible artifacts of data biases in the recent global surface warming hiatus Science 348 1469–72
CrossRef

Kelley C P, Mohtadi S, Cane M A, Seager R and Kushnir Y 2015 Climate change in the fertile crescent and implications of the recent syrian drought Proc. Natl Acad. Sci. USA 112 3241–6
CrossRef

Kjellstrom T, Lemke B and Otto M 2013 Mapping occupational heat exposure and effects in South-East Asia: ongoing time trends 1980–2011 and future estimates to 2050 Ind. Health 51 56–67
CrossRef

King A D, Donat M G, Fischer E M, Hawkins E, Alexander L V, Karoly D J, Dittus A J, Lewis S C and Perkins S E 2015 The timing of anthropogenic emergence in simulated climate extremes Environ. Res. Lett. 10 094015
IOPscience

Lafferty K D 2009 The ecology of climate change and infectious diseases Ecology 90 888–900
CrossRef

Liu Z et al 2015 Reduced carbon emission estimates from fossil fuel combustion and cement production in China Nature 524 335–8
CrossRef

Luginbuhl R, Jackson L, Castillo D and Loringer K 2008 Heat-related deaths among crop workers—United States, 1992–2006 J. Am. Med. Assoc. 300 1017–8
CrossRef

Lundgren K, Kuklane K, Gao C and Holmer I 2013 Effects of heat stress on working populations when facing climate change Ind. Health 51 3–15
CrossRef

Mahlstein I, Knutti R, Solomon S and Portmann R W 2011 Early onset of significant local warming in low latitude countries Environ. Res. Lett. 6 1–6
IOPscience

Mahlstein I, Hegerl G and Solomon S 2012 Emerging local warming signals in observational data Geophys. Res. Lett. 39 L21711
CrossRef

Matthews H D, Gillett N P, Stott P A and Zickfeld K 2009 The proportionality of global warming to cumulative carbon emissions Nature 459 829–32
CrossRef

Mayewski PA et al 2004 Holocene climate variability Quat. Res. 62 243–55
CrossRef

Mazdiyasni O and AghaKouchak A 2015 Substantial increase in concurrent droughts and heatwaves in the United States Proc. Natl Acad. Sci. USA 112 11484–9
CrossRef

McMichael C, Barnett J and McMichael A J 2012 An ill wind? climate change, migration, and health Environ. Health. Perspect. 120 646–54
CrossRef

Meehl G A, Arblaster J M, Fasullo J T, Hu A and Trenberth K E 2011 Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods Nat. Clim Change 1 360–4
CrossRef

National Research Council 2015 Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration (Washington DC: The National Academies Press) p 154 (www.nap.edu/catalog/18805/climate-intervention-carbon-dioxide-removal-and-reliable-sequestration)

Pal J S and Eltahir E A B 2016 Future temperature in southwest Asia projected to exceed a threshold for human adaptability Nature. Clim. Change 6 197–200
CrossRef

Peters G P 2008 From production-based to consumption-based national emission inventories Ecolog. Econ. 65 13–23
CrossRef

Pollard D, DeConto R M and Alley R B 2015 Potential Antarctic ice sheet retreat driven by hydrofracturing and ice cliff failure Earth Planet. Sci. Lett. 412 112–21
CrossRef

Rasmusson E M and Wallace J M 1983 Meteorological aspects of the El Niño/Southern oscillation Science 222 1195–202
CrossRef

Rhines A and Huybers P 2013 Frequent summer temperature extremes reflect changes in the mean, not the variance Proc. Natl Acad. Sci. USA 110 E546
CrossRef

Royal Society 2009 Geoengineering the Climate: Science, Governance, and Uncertainty (London: The Royal Society) p 82

Seneviratne S I, Donat M G, Mueller B and Alexander L V 2014 No pause in the increase of hot temperature extremes Nat. Clim Change 4 161–3
CrossRef

Sherwood SC and Huber M 2010 An adaptability limit to climate change due to heat stress Proc. Natl Acad. Sci. USA 107 9552–5
CrossRef

Sillmann J, Donat M G, Fyfe J C and Zwiers F W 2014 Observed and simulated temperature extremes during the recent warming hiatus Environ. Res. Lett. 9 1–8
IOPscience

Sillmann J, Lenton T M, Levermann A, Ott K, Hulme M, Benduhn F and Horton J B 2015 Climate emergencies do not justify engineering the climate Nat. Clim. Change. 5 290–2
CrossRef

UNFCCC 1992 United Nations Framework Convention on Climate Change (http://unfccc.int/essential_background/convention/items/6036.php)

Von Schuckmann K et al 2016 An imperative to monitor Earth’s energy imbalance Nat. Clim. Change 6 138–44
CrossRef



 



 

Share on Tumblr

 

 


Comments are moderated