Global Environmental Change and National Security of China

The concept of security has been redefined since the 1990s. As one of the important factors threatening human security, global environmental change has become a new challenge to the national security and social development. The national security problems caused by global environmental change, on one hand, are closely related to the global environmental problems, and, on the other hand, are manifested in the conflicts of international affairs. The global environmental change severely challenges the future development of China. When it comes to the study on human dimensions of global environmental change in China, much more attention should be paid to issues of important environmental change that may have great impacts on the national security of China, to the scientific assessment of the vulnerabilities of the natural and socialeconomic system of China to the impacts of global environmental change, and to the active establishment of the national risk management system, in which global environmental change should be included, so as to make contribution to sustainable development and construction of harmonious society of China.

Special Issue on "Response of Polar Organisms and Natural Environment to Global Changes"

High altitude and high latitude regions on Earth are experiencing rapid changes in climate, with impacts on polar organisms and the environment. The persistent cold and sometimes inhospitable conditions create unique ecosystems and habitats for polar organisms.

Inviting Contributions to a Special Issue on "Response of Polar Organisms and Natural Environment to Global Changes"

Dear Colleagues, We would like to invite you to submit manuscripts to a special issue of the journal Advances in Polar Science （APS） on ＂Response of Polar Organisms and Natural Environment to Global Changes＂.

The future of global land change monitoring

Land change science co-evolves with remote sensing technology.The world has witnessed an exponential growth in Earth observation satellites since 1972,and concurrently,land change research has experienced transformative advancement.This review summarizes the major milestones in global land cover and change mapping in a chronological order,from the pioneering efforts in the 1980s to the latest innovations at present,illustrating the tremendous progress in monitoring global land change from space.The second part of the review presents a critical synopsis of the recent progress in land change research,focusing on the technical aspects of temporal trends characterization,change mapping and area estimation,as well as the applied aspects of driver attribution and the complex consequences to the Earth system and human society.The last part of the article offers insights in the strategic directions of land change monitoring,including generation of analysis ready data,application of artificial intelligence algorithms,reconstruction of historical land change records,and near-real-time land change monitoring.Land change science will continue to play a vital role in addressing a wide range of global challenges,including climate change and carbon sequestration,food security,sustainable energy transition,natural disaster relief and environmental change in conflicted societies.

Plants and Global Environmental Change:A Special Issue Highlighting Younger Scientists

Humans are changing the global environment to such an extent that they are changing global climate （IPCC 2007; http：//www.ipcc.ch/）. The pace, if not the eventual extent, of this climate change may be rare in Earth＇s history, and these rapid changes in climate will have profound negative impacts on biodiversity of the planet and on the quality of human life （Millennium Ecosystem Assessment; http：llwww.maweb.orgll en/Index.aspx）. It is already widely believed that the Earth has entered a new geological period termed the Anthropocene, in recognition of the impact that humans are having on the Earth, and it is predicted that human-caused changes to Earth＇s environment and climate will likely be the foremost problems facing humans in the coming decades.

A long-term Global LAnd Surface Satellite(GLASS)data-set for environmental studies

Recently,five Global LAnd Surface Satellite(GLASS)products have been released:leaf area index(LAI),shortwave broadband albedo,longwave broadband emissivity,incident short radiation,and photosynthetically active radiation(PAR).The first three products cover the years 19822012(LAI)and 19812010(albedo and emissivity)at 15 km and 8-day resolutions,and the last two radiation products span the period 20082010 at 5 km and 3-h resolutions.These products have been evaluated and validated,and the preliminary results indicate that they are of higher quality and accuracy than the existing products.In particular,the first three products have much longer time series,and are therefore highly suitable for various environmental studies.This paper outlines the algorithms,product characteristics,preliminary validation results,potential applications and some examples of initial analysis of these products.

Geography Education for Sustainable Development

Increased pressure on the earth’s resources has led to what is increasingly referred to as the climate crisis.While a whole range of environmental parameters have been transformed through such pressures,the effect of human activities on the climate is symbolic of the nature of the human footprint upon our planet and makes the lack of any coherent political leadership in most countries even more alarming.The discipline of Geography has a distinct advantage in developing a more holistic understanding of global environmental challenges in that it reaches across all the sciences(including social sciences and humanities).Geographical education therefore represents an important vehicle for citizens of all ages to help them understand the complexity of the sustainability goal and what can(and should)be done to achieve a more sustainable future.In this essay,I reflect on three approaches that are available to individuals and communities towards taking the steps to sustainability.The philosophy embodied by the International Year of Global Understanding(IYGU)is suggested as a particularly valuable tool for geography educators.The activities of the International Geographical Union(IGU)offer important opportunities for geographers to learn from each other and promote best practice in geographical education.As‘the science for sustainability’,Geography has an increasingly important role to play in developing the knowledge and the skills to equip future generations with the tools to adapt to and mitigate potentially catastrophic global environmental change.

Web-system for processing and visualization of meteorological data for Siberian environment research

At present,mainly GIS software is used for exploration and visualization of spatially distributed data.At the same time an approach based on the combination of advanced web technologies along with the standard rules of information-computational system development is more suitable for performing tasks requiring more sophisticated data analysis.In this report,functional capabilities of the information-computational system created for meteorological and climatic data processing and online visualization are introduced.The system represents a dedicated web-interface,which allows performing of mathematical and statistical operations on the diverse observational and model data and to determine characteristics of global and regional climate changes.Currently such datasets as NCEP/NCAR Reanalysis,ECMWF ERA-40 Reanalysis,etc.are available for processing.In particular,the system allows calculating of temporal average and extremum values,time trends,etc.at arbitrary spatial and temporal ranges for different meteorological parameters.The possibility of online intercomparison of meteorological characteristics calculated for different datasets is also realized in the system.The final version of the system being developed is supposed to find application in meteorological and climatological investigations and should help researchers to save time during performing routine analytical tasks by simplifying handling of huge arrays of spatially distributed meteorological data.

A time series for monitoring vegetation activity and phenology at 10-daily time steps covering large parts of South America

It is widely accepted that natural resources should only be sustainably exploited and utilized to effectively preserve our planet for future generations.To better manage the natural resources,and to better understand the closely linked Earth systems,the concept of Digital Earth has been strongly promoted since US Vice President Al Gore’s speech in 1998.One core element of Digital Earth is the use and integration of remote sensing data.Only satellite imagery can cover the entire globe repeatedly at a sufficient high-spatial resolution to map changes in land cover and land use,but also to detect more subtle changes related for instance to climate change.To uncover global change effects on vegetation activity and phenology,it is important to establish high quality time series characterizing the past situation against which the current state can be compared.With the present study we describe a time series of vegetation activity at 10-daily time steps between 1998 and 2008 covering large parts of South America at 1 km spatial resolution.Particular emphasis was put on noise removal.Only carefully filtered time series of vegetation indices can be used as a benchmark and for studying vegetation dynamics at a continental scale.Without temporal smoothing,subtle spatio-temporal patterns in vegetation composition,density and phenology would be hidden by atmospheric noise and undetected clouds.Such noise is immanent in data that have undergone solely a maximum value compositing.Within the present study,the Whittaker smoother(WS)was applied to a SPOT VGT time series.The WS balances the fidelity to the observations with the roughness of the smoothed curve.The algorithm is extremely fast,gives continuous control over smoothness with only one parameter,and interpolates automatically.The filtering efficiently removed the negatively biased noise present in the original data,while preserving the overall shape of the curves showing vegetation growth and development.Geostatistical variogram analysis revealed a significantly increased signal-to-noise ratio compared to the raw data.Analysis of the data also revealed spatially consistent key phenological markers.Extracted seasonality parameters followed a clear meridional trend.Compared to the unfiltered data,the filtered time series increased the separability of various land cover classes.It is thus expected that the data set holds great potential for environmental and vegetation related studies within the frame of Digital Earth.

The ADV/ASV AATSR aerosol retrieval algorithm:current status and presentation of a full-mission AOD dataset

An advanced along-track scanning radiometer(AATSR)global multi-year aerosol retrieval algorithm is described.Over land,the AATSR dual-view(ADV)algorithm utilizes the measured top of the atmosphere(TOA)reflectance in both the nadir and forward views to decouple the contributions of the atmosphere and the surface to retrieve aerosol properties.Over ocean,the AATSR single-view(ASV)algorithm minimizes the discrepancy between the measured and modelled TOA reflectances in one of the views to retrieve the aerosol information using an ocean reflectance model.Necessary steps to process global,multiyear aerosol information are presented.These include cloud screening,the averaging of measured reflectance,and post-processing.Limitations of the algorithms are also discussed.The main product of the aerosol retrieval is the aerosol optical depth(AOD)at visible/near-infrared wavelengths.The retrieved AOD is validated using data from the surface-based AERONET and maritime aerosol network(MAN)sun photometer networks as references.The validation shows good agreement with the reference(r=0.85,RMSE=0.09 over land;r=0.83,RMSE=0.09 at coasts and r=0.96,RMSE=0.06 over open ocean).The results of the aerosol retrievals are presented for the full AATSR mission years 2002–2012 with seasonally averaged time series for selected regions.