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1.
We developed a volume-to-biomass method based on age groups representative of forest development stages to estimate live tree biomass, C, and biomass and C accumulation rates of Chinas forests between 1973 and 1993. The data were from plot-level forest inventory, national-level inventory statistics, and ecological site studies specified to estimate biomass in different tree components. Our results indicate that carbon storage in Chinas forests was 4.34 Pg C in the early 1990s, an increase of 13% since the early 1970s. The annual forest C sequestration rate from the late 1980s to early 1990s was 0.068 Pg C/yr and approximately four- to five-times higher than in the 1970s and 1980s. The large C sink in Chinas forests in the early 1990s was likely related to age structure changes that had developed to more productive stages, a consequence of reforestation and afforestation programs from the 1960s. The results were compared with other C store estimates, which were based on the same inventory data. Various methods can produce estimates that differ in the direction of C flux as well as its magnitude. Separating age groups with the volume–biomass method could cause a 27% difference in estimated carbon pools but an 89% difference in C sequestration rates whereas the biomass density method would provide an estimate that differs by 65% in the C pools. 相似文献
2.
On the basis of the analysis of atmospheric carbon dioxide concentration variations and the annual mean air temperature at Syowa Station, Antarctica in the period of 1984-1988, the following results are easily obtained:(1) The annual mean values of the atmospheric carbon dioxide concentration are gradually increased and equal to 342.59, 343.80, 345.15, 346.83 and 348.82 ppmv for 1984, 1985, 1986, 1987 and 1988, respectively. Its annual in-crease rates are 1.21, 1.35, 1.68 and 1.99 ppmv/yr. For 1984-1985, 1985-1986, 1986-1987 and 1987-1988, respectively and are raised year by year.The seasonal variations are observed and the maximum concentration is in spring and the minimum one is in late-summer or early-autumn.(2)The increasing tendency of the concentration of the atmospheric carbon dioxide is consistent with that of the air temperature. 相似文献
3.
Indigenous Australians’ knowledge of weather and climate 总被引：1，自引：1，他引：0
Although the last 200 years of colonisation has brought radical changes in economic and governance structures for thousands
of Aboriginal and Torres Strait Islanders living in remote areas of northern Australia, many of these Indigenous people still
rely upon, and live closely connected to, their natural environment. Over millennia, living ‘on country’, many of these communities
have developed a sophisticated appreciation of their local ecosystems and the climatic patterns associated with the changes
in them. Some of this knowledge is recorded in their oral history passed down through generations, documented in seasonal
weather calendars in local languages and, to a limited degree, transcribed and translated into English. This knowledge is
still highly valued by these communities today, as it is used to direct hunting, fishing and planting as well as to inform
many seasonally dependant cultural events. In recent years, local observations have been recognised by non-Indigenous scientists
as a vital source of environmental data where few historic records exist. Similar to the way that phenological observations
in the UK and US provide baseline information on past climates, this paper suggests that Indigenous observations of seasonal
change have the potential to fill gaps in climate data for tropical northern Australia, and could also serve to inform culturally
appropriate adaptation strategies. One method of recording recent direct and indirect climate and weather observations for
the Torres Strait Islands is documented in this paper to demonstrate the currency of local observations of climate and its
variability. The paper concludes that a comprehensive, participatory programme to record Aboriginal and Torres Strait Islander
knowledge of past climate patterns, and recent observations of change, would be timely and valuable for the communities themselves,
as well as contributing to a greater understanding of regional climate change that would be useful for the wider Australian
population. 相似文献
4.
Ines Bamberger Brian Oney Dominik Brunner Stephan Henne Markus Leuenberger Nina Buchmann Werner Eugster 《Boundary-Layer Meteorology》2017,164(1):135-159
Mountain-top observations of greenhouse gas mixing ratios may be an alternative to tall-tower measurements for regional scale source and sink estimation. To investigate the equivalence or limitations of a mountain-top site as compared to a tall-tower site, we used the unique opportunity of comparing in situ measurements of methane (\(\hbox {CH}_{4}\)) and carbon dioxide (\(\hbox {CO}_{2}\)) mixing ratios at a mountain top (986 m above sea level, a.s.l.) with measurements from a nearby (distance 28.4 km) tall tower, sampled at almost the same elevation (1009 m a.s.l.). Special attention was given to, (i) how local wind statistics and greenhouse gas sources and sinks at the mountain top influence the observations, and (ii) whether mountain-top observations can be used as for those from a tall tower for constraining regional greenhouse gas emissions. Wind statistics at the mountain-top site are clearly more influenced by local flow systems than those at the tall-tower site. Differences in temporal patterns of the greenhouse gas mixing ratios observed at the two sites are mostly related to the influence of local sources and sinks at the mountain-top site. Major influences of local sources can be removed by applying a statistical filter (\(5{\mathrm{th}}\) percentile) or a filter that removes periods with unfavourable flow conditions. In the best case, the bias in mixing ratios between the mountain-top and the tall-tower sites after the application of the wind filter was \({-}0.0005\pm 0.0010\) ppm for methane (September, 0000–0400 UTC) and \(0.11\pm 0.18\) ppm for \(\hbox {CO}_{2}\) (February, 1200–1600 UTC). Temporal fluctuations of atmospheric \(\hbox {CH}_{4}\) and \(\hbox {CO}_{2}\) mixing ratios at both stations also showed good agreement (apart from \(\hbox {CO}_{2}\) during summertime) as determined by moving bi-weekly Pearson correlation coefficients (up to 0.96 for \(\hbox {CO}_{2}\) and 0.97 for \(\hbox {CH}_{4}\)). When only comparing mixing ratios minimally influenced by local sources (low bias and high correlation coefficients), our measurements indicate that mountain-top observations are comparable to tall-tower observations. 相似文献
5.
Summary The surface low of a mature extra-tropical cyclone is often surmounted by a troposphere-spanning column of anomalously high
potential vorticity (PV). In this study the growth and decay of such a PV-tower is traced for one major North Atlantic frontal-wave
cyclone using the ECMWF analysis fields and adopting both Eulerian and Lagrangian frameworks.
A tower’s structure and composition relates intimately to the strength, scale and structure of the associated surface cyclone.
It is shown that the tower comprised a vertical superposition of three elements: (?) a quasi-seclusion of stratospheric air
extruded from an upper-level trough, (ℬ) a mid-tropospheric layer of intermingled air from diverse sources, but with a substantial
component originating from the system’s cold front, and (?) a low-tropospheric layer of diabatically-induced PV that was linked
to and originated from flow along a bent-back warm front.
An examination of the tower’s growth and decay helps identify the factors influencing the onset and rapidity of the cyclogenesis.
There was first an in-phase development of a surface baroclinic wave with the precursor of element (?), and also the emergence
of element (ℬ) in the form of a low-level elongated band of PV aligned along the cold front. Thereafter a short period of
rapid growth was marked by the appearance of a low-level band of PV along the warm front (element ?), and it co-spiraled with
and beneath the upper-level stratospheric intrusion (element ?). Demise of the tower followed a loss of amplitude of its central
portion and a loss of coherency aloft.
Evidence of the modulating as opposed to the dominating influence of diabatic processes upon the cyclone’s structure and strength
is derived from consideration of: the tower’s durable and ephemeral potential vorticity, the PV production along the warm
front, and sets of model simulations of the event that selectively suppress diabatic PV production.
Received July 9, 1999 Revised December 2, 1999 相似文献
6.
Carbon dioxide (CO2) sequestration has been proposed as a key component in technological portfolios for managing anthropogenic climate change, since it may provide a faster and cheaper route to significant reductions in atmospheric CO2 concentrations than abating CO2 production. However, CO2 sequestration is not a perfect substitute for CO2 abatement because CO2 may leak back into the atmosphere (thus imposing future climate change impacts) and because CO2 sequestration requires energy (thus producing more CO2 and depleting fossil fuel resources earlier). Here we use analytical and numerical models to assess the economic efficiency of CO2 sequestration and analyze the optimal timing and extent of CO2 sequestration. The economic efficiency factor of CO2 sequestration can be expressed as the ratio of the marginal net benefits of sequestering CO2 and avoiding CO2 emissions. We derive an analytical solution for this efficiency factor for a simplified case in which we account for CO2 leakage, discounting, the additional fossil fuel requirement of CO2 sequestration, and the growth rate of carbon taxes. In this analytical model, the economic efficiency of CO2 sequestration decreases as the CO2 tax growth rate, leakage rates and energy requirements for CO2 sequestration increase. Increasing discount rates increases the economic efficiency factor. In this simple model, short-term sequestration methods, such as afforestation, can even have negative economic efficiencies. We use a more realistic integrated-assessment model to additionally account for potentially important effects such as learning-by-doing and socio-economic inertia on optimal strategies. We measure the economic efficiency of CO2 sequestration by the ratio of the marginal costs of CO2 sequestration and CO2 abatement along optimal trajectories. We show that the positive impacts of investments in CO2 sequestration through the reduction of future marginal CO2 sequestration costs and the alleviation of future inertia constraints can initially exceed the marginal sequestration costs. As a result, the economic efficiencies of CO2 sequestration can exceed 100% and an optimal strategy will subsidize CO2 sequestration that is initially more expensive than CO2 abatement. The potential economic value of a feasible and acceptable CO2 sequestration technology is equivalent – in the adopted utilitarian model – to a one-time investment of several percent of present gross world product. It is optimal in the chosen economic framework to sequester substantial CO2 quantities into reservoirs with small or zero leakage, given published estimates of marginal costs and climate change impacts. The optimal CO2 trajectories in the case of sequestration from air can approach the pre-industrial level, constituting geoengineering. Our analysis is silent on important questions (e.g., the effects of model and parametric uncertainty, the potential learning about these uncertainties, or ethical dimension of such geoengineering strategies), which need to be addressed before our findings can be translated into policy-relevant recommendations. 相似文献
7.
The severe bora case that lasted from 13 to 15 November 2004 has been selected for the analysis of the bora of Pag’s ribs,
which occurs in the northern part of the eastern Adriatic coast over the Pag island area (Croatia). According to the measurements
from automatic stations, the MM5 numerical model is successful in the 10-min mean wind speed prediction at 10-m height. The
vertical analysis of the wind speed and potential temperature also gave satisfactory results. At the commencement of the bora
the modelled wind had a magnitude of 20ms−1 at 10-m height in the Pag island area, which sharply attenuated in the cross direction and to the open sea. In this way the
model has proved successful in predicting the characteristics of the bora of Pag’s ribs. Potential vorticity (PV) at 600m
has lower values within PV banners than during the developed bora. The consequence is a strong jet emanating from the nearest
gap. The vertical cross-sections through the centre of the gap point out a permanent hydraulic-like flow. At the time of the
bora of Pag’s ribs the highest modelled turbulent kinetic energy is found in the jump-like region above the inversion and
within the boundary layer along the lower boundary, ranging from 6–8m2 s−2. It is concluded that the dissipation in the hydraulic jumps and the wave breaking regions are the reasons for PV generation. 相似文献
8.
Environmental attitude and behavior are at the roots of a sustainable future, yet little is known about their developmental origins in early childhood. This longitudinal study is the first to examine how children’s environmental attitude and behavior develop throughout childhood (ages 7 to 18, N = 118). Environmental attitude and behavior form around the age of 7, increase until the age of 10, level off until the age of 14, and then decline again. Environmental behavior develops from childhood to early adolescence and starts consolidating from age 10 onwards, whereas environmental attitude remains in flux at least through early adulthood. 相似文献
9.
10.
D. G. Zamolodchikov V. I. Grabovskii G. N. Korovin M. L. Gitarskii V. G. Blinov V. V. Dmitriev W. A. Kurz 《Russian Meteorology and Hydrology》2013,38(10):701-714
Considered are the contribution of managed forests in the Russian Federation to the climate change softening and the forecast of their carbon-depositing potential in the period till 2050 under different scenarios of the forest management. The sink of CO2 to managed forests is estimated using the flow balance method. The CBM-CFS3 model worked out in the Canadian Forestry Service is used for predicting the carbon budget. It is found out that managed forests absorb 473.8 Mt of CO2 per year. The carbon sink is caused by the reduction of the volume of the forest use and by the regeneration of cutover stands of previous years. Depending on the conditions of the forest use, by 2020 the CO2 sink to managed forests will amount to 466–632 Mt/year and will be able to compensate from 21 to 29% of industrial emissions of greenhouse gases. The carbon absorption by managed forests will decrease to 105–235 Mt/year by 2050. To maintain and increase the carbon-depositing potential of managed forests, the Russian Federation needs the development of the system of purposeful activities on strengthening the protection against forest fires and on the intensification of forest reproduction. 相似文献
11.
In this essay we discuss the development of and estimation of uncertainties in the global surface temperature record. We briefly
discuss the similarities in and differences between the records from the institutions that produce such series. We then consider
the numerous issues that must be addressed to enable accurate estimates to be derived. We consider these in their order of
importance with respect to the record: biases in the sea surface temperature data, exposure of land-based thermometers before
about 1900, urbanization effects in some series, and, finally, the homogeneity of individual land-based records. 相似文献
12.
S. S. Krylov N. Yu. Bobrov G. V. Pryakhina S. S. Bricheva V. V. Ionov 《Russian Meteorology and Hydrology》2014,39(10):677-684
Presented are the results of the study of the processes of interaction between the river and sea water in the estuary of the Keret’ River flowing into the White Sea. The studies were carried out using the georadar method which enables one to register the boundary between fresh and salt water with the high spatial and temporal resolution. The use of this method helped to determine the boundaries of the area of distribution of fresh water in the estuary during different phases of the tidal cycle and to reveal the typical fluctuations of the boundary between fresh and salt water manifested at different values of river runoff and weather conditions. 相似文献
13.
A. Kasper-Giebl A. Koch R. Hitzenberger H. Puxbaum 《Journal of Atmospheric Chemistry》2000,35(1):33-46
Cloud water and interstitial aerosol samples collected at Mt. Sonnblick (SBO) were analyzed for sulfate and aerosol carbon to calculate in-cloud scavenging efficiencies. Scavenging efficiencies for sulfate (SO) ranged from 0.52 to 0.99 with an average of 0.80. Aerosol carbon was scavenged less efficiently with an average value (AC) of 0.45 and minimum and maximum values of 0.14 and 0.81, respectively. Both SO and AC showed a marked, but slightly different, dependence on the liquid water content (LWC) of the cloud. At low LWC, SO increased with rising LWC until it reached a relatively constant value of 0.83 above an LWC of 0.3 g/m3. In the case of aerosol carbon, we obtained a more gradual increase of AC up to an LWC of 0.5 g/m3. At higher LWCs, _ remained relatively constant at 0.60. As the differences between SO and A varied across the LWC range observed at SBO, we assume that part of the aerosol carbon was incorporated into the cloud droplets independently from sulfate. This hypothesis is supported by size classified aerosol measurements. The differences in the size distributions of sulfate and total carbon point to a partially external mixture. Thus, the different chemical nature and the differences in the size and mixing state of the aerosol particles are the most likely candidates for the differences in the scavenging behavior. 相似文献
14.
Agricultural expansion remains the most important proximate cause of tropical deforestation, while interactions between socio-economic, technological and institutional factors represent the fundamental drivers. Projected population increases could further raise the pressure on the remaining forests, unless agricultural intensification allows raising agricultural output without expanding agricultural areas. The purpose of this article is to understand the role of institutional factors in governing the intensification process towards the goal of preserving forests from agricultural pressures, with a focus on Indigenous Peoples’ and local communities’ rights to forests (as embedded in the various tenure regimes). In this paper we adopt an international dimension and analyse the process of agricultural expansion across eleven Latin American countries over the period 1990–2010 to assess whether, in a context of agricultural intensification, different land tenure regimes impact differently on the realization of land-sparing or Jevons paradox. The results, based on a number of multivariate statistical models that controls for socio-economic factors, strongly suggest that the formal recognition of Indigenous Peoples and local communities’ forest rights has played an important role in promoting land sparing or attenuating Jevons paradox. 相似文献
15.
Addressing climate change requires the synergy of technological, behavioural and market mechanisms. This article proposes a policy framework that integrates the three, deploying personal carbon trading as a key element within a policy portfolio to reduce personal carbon footprints. It draws on policy and human motivation literatures that address the behavioural changes that may be needed in the context of a long-term threat such as climate change. This proposal builds on an analysis of the British Columbia carbon tax, international examples of carbon pricing instruments and strategies for behavioural change such as social networks, loyalty management, mobile apps and gamification. Interviews were conducted with experts in financial services, energy conservation and clean technology, as well as with specialists in climate, health and taxation policy. Their input, together with a review of the theoretical literature and practical case studies, informed the proposed design of a Carbon, Health and Saving System for promoting individual engagement and collective action by linking long-term climate mitigation measures with short-term personal and social goals, including health, recreation and social reinforcement.Policy RelevanceThis article identifies areas for climate policy innovation and recommends policies that can support, promote and enable personal carbon budgeting and collective action. Although this study is focused on British Columbia, both the input provided by key opinion leaders and the proposed framework are applicable to other jurisdictions.This policy proposal shows how personal carbon trading could work in the context of a Canadian province with an existing climate mitigation policy. It also specifies a minimum viable product approach to establishing the economic, social and technological foundations for personal carbon trading.The Carbon, Health and Saving System identifies the technologies and stakeholders needed to implement personal carbon trading, and offers the possibility of motivating a widespread conscious human response in the event that carbon taxation proves insufficient to generate economic adaptation in a changing climate. 相似文献
16.
Aircraft observations of the atmospheric boundary layer (ABL) over Arctic sea ice were made during non-stationary conditions
of cold-air advection with a cloud edge retreating through the study region. The sea-ice concentration, roughness, and ABL
stratification varied in space. In the ABL heat budget, 80% of the Eulerian change in time was explained by cold-air advection
and 20% by diabatic heating. With the cloud cover and inflow potential temperature profile prescribed as a function of time,
the air temperature and near-surface fluxes of heat and momentum were well simulated by the applied two-dimensional mesoscale
model. Model sensitivity tests demonstrated that several factors can be active in generating unstable stratification in the
ABL over the Arctic sea ice in March. In this case, the upward sensible heat flux resulted from the combined effect of clouds,
leads, and cold-air advection. These three factors interacted non-linearly with each other. From the point of view of ABL
temperatures, the lead effect was far less important than the cloud effect, which influenced the temperature profiles via
cloud-top radiative cooling and radiative heating of the snow surface. The steady-state simulations demonstrated that under
overcast skies the evolution towards a deep, well-mixed ABL may take place through the merging of two mixed layers one related
to mostly shear-driven surface mixing and the other to buoyancy-driven top-down mixing due to cloud-top radiative cooling. 相似文献
17.
K. P. Tyshko 《Russian Meteorology and Hydrology》2009,34(8):534-540
Structural-genetic types of hummocks formed on the Arctic seas’ ice cover are considered. A method of the laboratory physical
modeling was used for understanding kinematic schemes of the hummocks’ formation processes. A methodology of computation of
the hummock consolidation intensity for different hummocks’ structural types was proposed. The performed computations showed
good coherence of the laboratory experiments results and field studies of hummocks’ structure in the Barents and Kara seas. 相似文献
18.
The Stern Review has played an enormous role in making the world of business aware of the challenge of long-term climate change. In order to make real progress on the basis of this awareness, it is important to pay attention to the difference between human suffering and losses of gross domestic product (GDP). The Review has compared climate change to experiences of suffering like World War I. That war, however, hardly affected global GDP. The long-term damages to be expected from business-as-usual greenhouse gas emissions include loss of the coastal cities of the world over the next millennia. This would be an act of unprecedented barbarism, regardless of whether it would slow down economic growth or perhaps even accelerate it. Business leaders worried about climate change need to pay attention to the tensions between ethical and economic concerns. Otherwise, a credibility crisis threatens global climate policy. An important step to establish the credibility needed for effective climate policy will be to gradually move towards a regime where emission permits are auctioned, not handed out as hidden subsidies. The revenues generated by permit auctions should be used to establish a global system of regional climate funds. 相似文献
19.
20.
Partitioning of semivolatile organic compounds between gas, organic aerosol, and aqueous aerosol phases has been described in atmospheric models using Raoult’s Law and/or Henry’s Law, with activity coefficients accounting for nonideal behavior in the aerosol solutions. Raoult’s Law and Henry’s Law are thermodynamically consistent with each other as long as the parameters defining their different reference states are accurately known. Unfortunately, saturation vapor pressures, Henry’s law constants, and activity coefficients for organic aerosol compounds must typically be estimated. As a result, thermodynamic inconsistencies can arise when using Raoult’s and Henry’s Law approaches together due to errors in estimation methods. A test of predicted partitioning parameters for representative semivolatile organics suggests overall errors of at least an order of magnitude. Box model simulations with a simplified partitioning scenario demonstrate that these estimation errors can significantly alter partitioning for many compounds and, more importantly, that thermodynamic inconsistencies will lead to even greater errors than those due solely to uncertain parameters. To avoid these errors, a common reference state should be used to define equilibrium among all phases, improved estimation methods and measurements should continue to be pursued, and alternative reference states that better represent typical organic aerosol mixtures should be explored. 相似文献