Calculating Historical Contributions To Climate Change – Discussing The ‘Brazilian Proposal’

This paper discusses methodological issues relevant to the calculation of historical responsibility of countries for climate change (‘The Brazilian Proposal’). Using a simple representation of the climate system, the paper compares contributions to climate change using different indicators: current radiative forcing, current GWP-weighted emissions, radiative forcing from increased concentrations, cumulative GWP-weighted emissions, global-average surface-air temperature increase and two new indicators: weighted concentrations (analogue to GWP-weighted emissions) and integrated temperature increase. Only the last two indicators are at the same time ‘backward looking’ (take into account historical emissions), ‘backward discounting’ (early emissions weigh less, depending on the decay in the atmosphere) and ‘forward looking’ (future effects of the emissions are considered) and are comparable for all gases. Cumulative GWP-weighted emissions are simple to calculate but are not ‘backward discounting’. ‘Radiative forcing’ and ‘temperature increase’ are not ‘forward looking’. ‘Temperature increase’ discounts the emissions of the last decade due to the slow response of the climate system. It therefore gives low weight to regions that have recently significantly increased emissions. Results of the five different indicators are quite similar for large groups (but possibly not for individual countries): industrialized countries contributed around 60% to today’s climate change, developing countries around 40% (using the available data for fossil, industrial and forestry CO₂, CH₄ and N₂O). The paper further argues including non-linearities of the climate system or using a simplified linear system is a political choice. The paper also notes that results of contributions to climate change need to be interpreted with care: Countries that developed early benefited economically, but have high historical emission, and countries developing at a later period can profit from developments in other countries and are therefore likely to have a lower contribution to climate change.     

An assessment of potential change in wildfire activity in the Russian boreal forest zone induced by climate warming during the twenty-first century

The problem of forest fires is very important for Russia. In this paper we consider this problem in the connection with the projection of significant climate change. An approach to determine the magnitude of change in wildfire risk in Russia under the influence of climate warming is discussed. Observations for the European part of Russia and for Siberia have been used in this analysis. A statistical correlation between drought indices calculated by use of monthly sums of temperature and precipitation and the frequency of fire danger was obtained for the forest zone of Russia. The change in fire danger potential was evaluated using temperature and precipitation monthly means at the nodes of a regular spatial grid. Climate change scenarios were obtained from Global Climate Models (GCM) ensemble projections. The maximum increases (about 12–30%) of the number of days with fire danger conditions during the twenty-first century fire season were obtained for the southern forest zone boundary in both the European region of Russia and in Siberia. In the Baikal and Primoriye Regions, fire danger distributions in the twenty-first century are not projected to change significantly.     

Infinite uncertainty,forgotten feedbacks,and cost-benefit analysis of climate policy

Tol (2003) questioned the applicability of expected cost-benefit analysis to global mitigation policy when he found evidence that the uncertainty surrounding estimates of the marginal damage of climate change could be infinite even if total damages were finite. Yohe (2003) suggested that this problem could be alleviated if international development aid were directed at eliminating the source of the problem – climate induced negative growth rates in a few regions along a handful of troublesome scenarios. The hypothesis about adding a second policy lever to the climate policy calculus is shown to hold, though perhaps not as robustly as originally thought. A portfolio of international policies with at least two independent tools can avoid infinite uncertainty on the margins and the associated implications for global mitigation policy at a reasonable price even in the relatively unlikely event that climate change causes negative economic growth in a region or two. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Adaptation in agriculture: lessons for resilience from eastern regions of New Zealand

Assessments of adaptation in agriculture have evolved considerably from early, top-down, impact assessments. These early assessments, internationally and in New Zealand, provided a limited view of ‘smart farmer’ adaptation. While impact assessment provides some useful insights, experience with vulnerability and adaptation assessment provides a more appropriate foundation for understanding and characterising practical smart farmer adaptation. Findings are presented from 8 years of engagement with farmers in eastern regions of New Zealand. A comprehensive farm resilience picture has emerged from this work. This picture reflects a strong belief from real-world smart farmers that there is sufficient knowledge and experience to adapt to climate change. Proactive farmers are already reading multiple signals, including changes in climate, and are responding. The farm resilience picture provides a foundation for exploring alternative adaptation options and pathways for agriculture. These are presented and discussed in response to two proposed climate change scenarios, a high carbon world scenario and a rapidly decarbonising world scenario. Knowledge intensive, low input systems are consistent with the resilience picture drawn from farmers. Such systems are also consistent with a rapidly decarbonising world scenario and, it is argued, are likely to become increasingly attractive under a high carbon world scenario. A smart farming approach, focused on resilience, provides the basis for development of a response capacity, with potentially significant co-benefits in terms of adaptation and mitigation to climate change. Wider issues and needs to support the further development of farm resilience, and more widely landscape or regional resilience, are identified and discussed. It is apparent from this work that ongoing engagement with smart farmers, focused on resilience, can contribute significantly to development of a coordinated ‘bottom up’ and ‘top down’ response capacity. Addressing the psychology of change is a fundamental need to ensure wider engagement.     

大兴安岭气候干湿变化及对森林火灾的影响

明确气候变化背景下大兴安岭林区气候干湿状况特征,揭示其对森林火灾的影响,可为该区域森林火灾管理和森林资源保护提供科学依据。基于大兴安岭林区1974—2016年标准化降水指数（SPI）,采用统计分析和对比分析方法,系统研究不同干湿情景对森林火灾发生次数及过火面积的影响,并讨论不同等级干旱对其影响的异同性。结果表明:1974—2016年,年、季尺度上大兴安岭林区气候均呈湿润化趋势。森林火灾发生次数多（少）和过火面积大（小）与气候的干湿状况（等级）基本一致,但森林火灾的发生次数与气候干湿状况相关更为密切。年尺度上,SPI与火灾次数呈负相关,与过火面积的自然对数则呈较弱的负相关;季尺度上,各季节SPI与对应的林火次数和过火面积自然对数均呈显著的负相关,但与过火面积的相关程度差异较大,以春季相关最为显著,秋季次之,夏季则相对较弱;不同季节SPI与年林火次数和过火面积自然对数呈负相关,前一年冬季SPI对当年火灾次数的贡献最大。可见,气候干湿状况对森林火灾的影响存在明显的滞后效应。SPI不仅能较好地反映区域气候的干湿状况,亦能较好地指示森林火灾发生的可能性及发生火灾的过火面积的相对变化情况,可为森林火灾预测和管理提供科学依据。     

Potential effect of climate change on observed fire regimes in the Cordilleran forests of South-Central Interior, British Columbia

Climate change is predicted to result in a warmer and drier climate in many parts of the world, including south-central British Columbia. With a shift in climate, a change in fire regimes is likely to occur. In this study, a statistically significant increase in mean fire size was predicted to occur along with an increase maximum fire size and decrease in the mean fire interval. A change in these fire regime characteristics suggests a climate-change driven shift in fire regimes may occur by the 2020s. The shift in fire regime suggests the proportion of the landscape burning every 50 years or less will increase from 34 % to 93 % by the 2080s. Change in fire regimes will have direct implications for ecosystem management as the combination of large, flammable fuel types and fire-prone climatic conditions will increase the risk of larger more frequent fires and increase the costs and dangers involved in managing fire-prone forests in the Cordilleran region of south-central British Columbia. The climate change-driven shift in fire regime questions the use of historic fire regime characteristics for determining landscape-level conservation targets within the study area.     

Fire activity in Borneo driven by industrial land conversion and drought during El Niño periods, 1982–2010

Tropical rainforests, naturally resistant to fire when intact, are increasingly vulnerable to burning due to ongoing forest perturbation and, possibly, climatic changes. Industrial-scale forest degradation and conversion are increasing fire occurrence, and interactions with climate anomalies such as El Niño induced droughts can magnify the extent and severity of fire activity. The influences of these factors on fire frequency in tropical forests has not been widely studied at large spatio-temporal scales at which feedbacks between fire reoccurrence and forest degradation may develop. Linkages between fire activity, industrial land use, and El Niño rainfall deficits are acute in Borneo, where the greatest tropical fire events in recorded history have apparently occurred in recent decades. Here we investigate how fire frequency in Borneo has been influenced by industrial-scale agricultural development and logging during El Niño periods by integrating long-term satellite observations between 1982 and 2010 – a period encompassing the onset, development, and consolidation of its Borneo’s industrial forestry and agricultural operations as well as the full diversity of El Niño events. We record changes in fire frequency over this period by deriving the longest and most comprehensive spatio-temporal record of fire activity across Borneo using AVHRR Global Area Coverage (GAC) satellite data. Monthly fire frequency was derived from these data and modelled at 0.04° resolution via a random-forest model, which explained 56% of the monthly variation as a function of oil palm and timber plantation extent and proximity, logging intensity and proximity, human settlement, climate, forest and peatland condition, and time, observed using Landsat and similar satellite data. Oil-palm extent increased fire frequency until covering 20% of a grid cell, signalling the significant influence of early stages of plantation establishment. Heighted fire frequency was particularly acute within 10 km of oil palm, where both expanding plantation and smallholder agriculture are believed to be contributing factors. Fire frequency increased abruptly and dramatically when rainfall fell below 200 mm month⁻¹, especially as landscape perturbation increased (indicated by vegetation index data). Logging intensity had a negligible influence on fire frequency, including on peatlands, suggesting a more complex response of logged forest to burning than appreciated. Over time, the epicentres of high-frequency fires expanded from East Kalimantan (1980’s) to Central and West Kalimantan (1990’s), coincidentally but apparently slightly preceding oil-palm expansion, and high-frequency fires then waned in East Kalimantan and occurred only in Central and West Kalimantan (2000’s). After accounting for land-cover changes and climate, our model under-estimates observed fire frequency during ca. 1990–2002 and over-estimates it thereafter, suggesting that a multi-decadal shift to industrial forest conversion and forest landscapes may have diminished the propensity for high-frequency fires in much of this globally significant tropical region since ca. 2000.     

“A convenient truth”: air travel passengers’ willingness to pay to offset their CO<Subscript>2</Subscript> emissions

Several economic reviews demonstrate the substantial costs related to climate change and consequently call for early action. These reviews, however, have been limited to measuring ‘objective’ risks and expected material damage related to climate change. The ‘subjective’ perceived risk of climate change and society’s willingness to pay (WTP) to avoid these risks are expected to provide an important additional motivation for direct action. We investigate whether and why air travel passengers—an increasingly important source of greenhouse gas emissions—are supportive of measures that increase the cost of their travel based on the polluter pays principle and compensate the damage caused by their flight. Compared to the results of the few previous studies that have elicited WTP estimates for climate policy more generally, our results appear to be at the lower end of the scale, while a comparison to estimates of the social cost of carbon shows that the average WTP estimate in this study is close to the estimated marginal damage cost. Although significant differences are found between travellers from Europe, North America, Asia and the rest of the world, we show that there exists a substantial demand for climate change mitigation action. The positive risk premium over and above the expected property damage cost assessments should be accounted for more explicitly in economic reviews as it will add to the burden of proof of direct action. Measurements of passenger WTP will help policy makers to design effective financial instruments aimed at discouraging climate-unfriendly travel activities as well as to generate funds for the measures directed at climate change mitigation and adaptation. Based on stated WTP by travellers to offset their greenhouse gas emissions, funds in the order of magnitude of €23 billion could be generated annually to finance climate change mitigation activities.     

Impact of climate variability on summer fires in a Mediterranean environment (northeastern Iberian Peninsula)

We analyse the impact of climate interannual variability on summer forest fires in Catalonia (northeastern Iberian Peninsula). The study period covers 25 years, from 1983 to 2007. During this period more than 16000 fire events were recorded and the total burned area was more than 240 kha, i.e. around 7.5% of whole Catalonia. We show that the interannual variability of summer fires is significantly correlated with summer precipitation and summer maximum temperature. In addition, fires are significantly related to antecedent climate conditions, showing positive correlation with lagged precipitation and negative correlation with lagged temperatures, both with a time lag of two years, and negative correlation with the minimum temperature in the spring of the same year. The interaction between antecedent climate conditions and fire variability highlights the importance of climate not only in regulating fuel flammability, but also fuel structure. On the basis of these results, we discuss a simple regression model that explains up to 76% of the variance of the Burned Area and up to 91% of the variance of the number of fires. This simple regression model produces reliable out-of-sample predictions of the impact of climate variability on summer forest fires and it could be used to estimate fire response to different climate change scenarios, assuming that climate-vegetation-humans-fire interactions will not change significantly.     

Management alternatives to offset climate change effects on Mediterranean fire regimes in NE Spain

Fire regime is affected by climate and human settlements. In the Mediterranean, the predicted climate change is likely to exacerbate fire prone weather conditions, but the mid- to long-term impact of climate change on fire regime is not easily predictable. A negative feedback via fuel reduction, for instance, might cause a non-linear response of burned area to fire weather. Also, the number of fires escaping initial control could grow dramatically if the fire meteorology is just slightly more severe than what fire brigades are prepared for. Humans can directly influence fire regimes through ignition frequency, fire suppression and land use management. Here we use the fire regime model FIRE LADY to assess the impacts of climate change and local management options on number of fires, burned area, fraction of area burned in large fires and forest area during the twenty-first century in three regions of NE Spain. Our results show that currently fuel-humidity limited regions could suffer a drastic shift of fire regime with an up to 8 fold increase of annual burned area, due to a combination of fuel accumulation and severe fire weather, which would result in a period of unusually large fires. The impact of climate change on fire regime is predicted to be less pronounced in drier areas, with a gradual increase of burned area. Local fire prevention strategies could reduce but not totally offset climate induced changes in fire regimes. According to our model, a combination of restoring the traditional rural mosaic and classical fire prevention would be the most effective strategy, as a lower ignition frequency reduces the number of fires and the creation of agricultural fields in marginal areas reduces their extent.     

Probabilistic Inference for Future Climate Using an Ensemble of Climate Model Evaluations

This paper describes an approach to computing probabilistic assessments of future climate, using a climate model. It clarifies the nature of probability in this context, and illustrates the kinds of judgements that must be made in order for such a prediction to be consistent with the probability calculus. The climate model is seen as a tool for making probabilistic statements about climate itself, necessarily involving an assessment of the model’s imperfections. A climate event, such as a 2^{^}C increase in global mean temperature, is identified with a region of ‘climate-space’, and the ensemble of model evaluations is used within a numerical integration designed to estimate the probability assigned to that region.     

Climate simulations for 1880–2003 with GISS modelE

We carry out climate simulations for 1880–2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880–2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Lost in translation? United States television news coverage of anthropogenic climate change, 1995–2004

Eminent climate scientists have come to consensus that human influences are significant contributors to modern global climate change. This study examines coverage of anthropogenic climate change in United States (U.S.) network television news – ABC World News Tonight, CBS Evening News and NBC Nightly News – and focuses on the application of the journalistic norm of ‘balance’ in coverage from 1995 through 2004. This study also examines CNN WorldView, CNN Wolf Blitzer Reports and CNN NewsNight as illustrations of cable news coverage. Through quantitative content analysis, results show that 70% of U.S. television news segments have provided ‘balanced’ coverage regarding anthropogenic contributions to climate change vis-à-vis natural radiative forcing, and there has been a significant difference between this television coverage and scientific consensus regarding anthropogenic climate change from 1996 through 2004. Thus, by way of the institutionalized journalistic norm of balanced reporting, United States television news coverage has perpetrated an informational bias by significantly diverging from the consensus view in climate science that humans contribute to climate change. Troubles in translating this consensus in climate science have led to the appearance of amplified uncertainty and debate, also then permeating public and policy discourse.     

Modeling the Impact of Black Spruce on the Fire Regime of Alaskan Boreal Forest

In the boreal biome, fire is the major disturbance agent affecting ecosystem change, and fire dynamics will likely change in response to climatic warming. We modified a spatially explicit model of Alaskan subarctic treeline dynamics (ALFRESCO) to simulate boreal vegetation dynamics in interior Alaska. The model is used to investigate the role of black spruce ecosystems in the fire regime of interior Alaska boreal forest. Model simulations revealed that vegetation shifts caused substantial changes to the fire regime. The number of fires and the total area burned increased as black spruce forest became an increasingly dominant component of the landscape. The most significant impact of adding black spruce to the model was an increase in the frequency and magnitude of large-scale burning events (i.e., time steps in which total area burned far exceeded the normal distribution of area burned). Early successional deciduous forest vegetation burned more frequently when black spruce was added to the model, considerably decreasing the fire return interval of deciduous vegetation. Ecosystem flammability accounted for the majority of the differences in the distribution of the average area burned. These simulated vegetation effects and fire regime dynamics have important implications for global models of vegetation dynamics and potential biotic feedbacks to regional climate.     

A rose by any other name ...?: What members of the general public prefer to call “climate change”

Unlike many other environmental problems, the terms used to describe the phenomenon of increasing atmospheric concentrations of anthropogenic greenhouse gases are many, with multiple and sometimes conflicting meanings. Whether there are meaningful distinctions in public perceptions of “global warming,” “climate change,” and “global climate change” has been a topic of research over the past decade. This study examines public preferences for these terms based on respondent characteristics, including climate change beliefs, political affiliation, and audience segment status derived from the “Global Warming’s Six Americas” classification. Certainty of belief in global warming, political affiliation and audience segment status were found to be the strongest predictors of preference, although “I have no preference” was the modal response. Global warming appears to be a more polarizing term than climate change, preferred most by people already concerned about the issue, and least by people who don’t believe climate change is occurring. Further research is needed to identify which of these two names promotes the engagement of people across the spectrum of climate change beliefs in constructive dialogue about the issue.     

Climatic change: communication changes over this journal’s first ‘century’

Over the century of ‘Climatic Change’ volumes and the 33 years that they span the climate has changed. Here I consider the challenge of interdisciplinary communication to which the first 99 volumes of this journal are dedicated. Have we succeeded and have climatic change researchers shared findings with a broader audience? If this journal has been successful, should the editorial board and publishers now consider new modes of communicating research to a still wider public, say by hiring a communication cartoonist or with an interactive blog?     

Changes in fire regimes since the Last Glacial Maximum: an assessment based on a global synthesis and analysis of charcoal data

Fire activity has varied globally and continuously since the last glacial maximum (LGM) in response to long-term changes in global climate and shorter-term regional changes in climate, vegetation, and human land use. We have synthesized sedimentary charcoal records of biomass burning since the LGM and present global maps showing changes in fire activity for time slices during the past 21,000 years (as differences in charcoal accumulation values compared to pre-industrial). There is strong broad-scale coherence in fire activity after the LGM, but spatial heterogeneity in the signals increases thereafter. In North America, Europe and southern South America, charcoal records indicate less-than-present fire activity during the deglacial period, from 21,000 to ∼11,000 cal yr BP. In contrast, the tropical latitudes of South America and Africa show greater-than-present fire activity from ∼19,000 to ∼17,000 cal yr BP and most sites from Indochina and Australia show greater-than-present fire activity from 16,000 to ∼13,000 cal yr BP. Many sites indicate greater-than-present or near-present activity during the Holocene with the exception of eastern North America and eastern Asia from 8,000 to ∼3,000 cal yr BP, Indonesia and Australia from 11,000 to 4,000 cal yr BP, and southern South America from 6,000 to 3,000 cal yr BP where fire activity was less than present. Regional coherence in the patterns of change in fire activity was evident throughout the post-glacial period. These complex patterns can largely be explained in terms of large-scale climate controls modulated by local changes in vegetation and fuel load. The readers are requested to refer to the section “List of contributors” for the complete list of author affiliation details.     

Climate Change and People-Caused Forest Fire Occurrence in Ontario

Climate change that results from increasing levels of greenhouse gases in the atmosphere has the potential to increase temperature and alter rainfall patterns across the boreal forest region of Canada. Daily output from the Canadian Climate Centre coupled general circulation model (GCM) and the Hadley Centre's HadCM3 GCM provided simulated historic climate data and future climate scenarios for the forested area of the province of Ontario, Canada. These models project that in climates of increased greenhouse gases and aerosols, surface air temperatures will increase while seasonal precipitation amounts will remain relatively constant or increase slightly during the forest fire season. These projected changes in weather conditions are used to predict changes in the moisture content of forest fuel, which influences the incidence of people-caused forest fires. Poisson regression analysis methods are used to develop predictive models for the daily number of fires occurring in each of the ecoregions across the forest fire management region of Ontario. This people-caused fire prediction model, combined with GCM data, predicts the total number of people-caused fires in Ontario could increase by approximately 18% by 2020–2040 and50% by the end of the 21st century.     

The ‘Little Ice Age’ glacial expansion in western Scandinavia: summer temperature or winter precipitation?

Reconstructing the temporal and spatial climate development on a seasonal basis during the last few centuries, including the ‘Little Ice Age’, may help us better understand modern-day interplay between natural and anthropogenic climate variability. The conventional view of the climate development during the last millennium has been that it followed a sequence of a Medieval Warm Period, a cool ‘Little Ice Age’ and a warming during the later part of the 19th century and in particular during the late 20th/early 21st centuries. However, recent research has challenged this rather simple sequence of climate development. Up to the present, it has been considered most likely that the ‘Little Ice Age’ glacial expansion in western Scandinavia was due to lower summer temperatures. Data presented here, however, indicate that the main cause of the early 18th century glacial advance in western Scandinavia was mild and humid winters associated with increased precipitation and high snowfall on the glaciers.     

A Regional, Multi-sectoral And Integrated Assessment Of The Impacts Of Climate And Socio-economic Change In The Uk

Policy makers and stakeholders are increasingly demanding impact assessments which produce policy-relevant guidance on the local impacts of global climate change. The ‘Regional Climate Change Impact and Response Studies in East Anglia and North West England’ (RegIS) study developed a methodology for stakeholder-led, regional climate change impact assessment that explicitly evaluated local and regional (sub-national) scale impacts and adaptation options, and cross-sectoral interactions between four major sectors driving landscape change (agriculture, biodiversity, coasts and floodplains and water resources). The ‘Drivers-Pressure-State-Impact-Response’ (DPSIR) approach provided a structure for linking the modelling and scenario techniques. A 5 × 5 km grid was chosen for numerical modelling input (climate and socio-economic scenarios) and output, as a compromise between the climate scenario resolution (10 × 10 km) and the detailed spatial resolution output desired by stakeholders. Fundamental methodological issues have been raised by RegIS which reflect the difficulty of multi-sectoral modelling studies at local scales. In particular, the role of scenarios, error propagation in linked models, model validity, transparency and transportability as well as the use of integrated assessment to evaluate adaptation options to climate change are examined. Integrated assessments will provide new insights which will compliment those derived by more detailed sectoral assessments.