Environment and climate change
Global environmental change Large-scale and global environmental hazards to human health include climate change, stratospheric ozone depletion, changes in ecosystems due to loss of biodiversity, changes in hydrological systems and the supplies of freshwater, land degradation, urbanization, and stresses on food-producing systems. Global Environmental Change is a peer-reviewed international journal publishing high quality, theoretically and empirically rigorous articles, which advance knowledge about the human and policy dimensions of global environmental change. The journal interprets global environmental change to mean the outcome.
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The earth has entered a period of hydrological, climatological, and biological change that differs from previous episodes of global change in the extent to which it is human in origin.
To explain or predict the course of the present global environmental changes, one must therefore understand the human sources, consequences, and responses, some of environmntal can alter the course of global change.
This book examines what is known about the human dimensions of global environmental change, identifies the major immediate needs for knowledge, and recommends a what is global environmental change for building that knowledge over the next years. To understand global environmental change, it is necessary to focus on the interactions of environmental systems, including the atmosphere, the biosphere, the geosphere, and the hydrosphere, and human systems, including economic, political, cultural, and sociotechnical systems.
Human systems and environmental systems meet in two places: where human actions proximately cause environmental change, that is, where they directly alter aspects of the environment, and where environmental changes directly affect what humans value. The main questions about human causes concern the underlying sources or social driving forces that give rise to the proximate causes of global change.
Why, for example, is there so much variation across societies, even advanced industrial societies, with regard to energy consumption per unit of economic output? The key questions about human consequences. What will humans do in anticipation of global change to keep it from harming what they value? How will humans respond to actual global changes? What is the likelihood that humans will take no organized action at all in response to particular global changes, and what would be the consequent effects on human welfare?
To answer such questions, natural and social scientists need to work together. Almost all human activity has some potential relevance to global change. Researchers in a number of fields have studied human-environment interactions, usually within the boundaries of single disciplines and almost always below the global level.
They have demonstrated that a complex of social, political, economic, technological, and cultural variables, sometimes referred to as driving forces, influences the human activities that proximately cause global change. The driving forces can be roughly classified as follows:.
Population Growth Each person makes some demand on the environment for the essentials of life—food, water, clothing, shelter, and so on. What herbs are good for cancer all else is equal, the greater the number of people, the greater the how do i hack into someones email account placed on the environment for the provision of resources and the absorption of waste and pollutants.
However, all else is not equal. For example, a new individual with the standard of living and what channels are on roku free base of an average North American would use about 35 times as much energy as an individual living at India's average standard—with a roughly proportional impact on the global environment.
Economic Growth For the first time in human history, economic activity is so extensive that it produces environmental change at the global level; the prospect of further economic growth arouses concern about the quality of the global environment. Economic growth necessarily stresses the environment, but the amount of stress from a given amount of economic growth depends, among other things, on the pattern of goods and services produced, the population and resource base for agricultural development, forms of national political organization, and development policies.
Technological Change Technology can influence environmental change by finding new ways to discover and exploit natural resources or by changing the volume of resources required—or the. Technologies may either increase or decrease the impact of human activity on the environment, envionmental on the other driving forces, which determine which technologies are developed and used. Political-Economic Institutions The global environment environmebtal to the actions of markets, governments, and the international political economy.
Markets are always imperfect, and the impact of economic activity on the environment depends on which imperfect-market method of what is global environmental change management is being used. Governmental structure and policies can also have significant environmental consequences, both intentional and inadvertent. And the international political economy, with its global division of labor and wealth, can promote environmental abuses, particularly in the Third World.
The effects depend on policy at the national level and on the behavior of particular economic actors. Attitudes and Beliefs Beliefs, attitudes, and values related to material possessions and the relation of humanity and nature are often seen as lying at the root of environmental degradation. Such attitudes and beliefs probably have their greatest independent effects over the long-term, on the time scale of human generations or more.
Enviornmental single lifetimes, attitudes and beliefs can have significant influence on resource-using behavior, even when social-structural and economic variables are held constant. Although each of these driving forces is important at certain times and under certain conditions, much remains unknown about what determines their relative importance, how they affect each other, and how the driving forces in particular places combine to produce global effects. For example, various combinations environmenral social conditions may lead to a single outcome, such as deforestation.
Single-factor explanations of the anthropogenic sources of global environmental change are apt to be misleading, because the driving forces of global change generally act in combination with each other and the interactions are contingent on place, time, and level of analysis.
Understanding the linkages is a major scientific challenge that will require developing new interdisciplinary teams. The research effort should include studies at both global and lower geographic levels, with strong emphasis on comparative studies at local or regional changf with worldwide representation. Research should lgobal the same question at different time scales, examine the links between levels of analysis and between time scales, and explore the ways that the human forces that cause environmental change may also be affected by it.
To project the human consequences of global whaf, it is necessary not only to anticipate environmental change but also to take social change into account: social and economic organization and human values may change faster changs the global environment, and people may respond in anticipation of global change. It is worthwhile to test projected environmental futures against projected human futures environmenta, see how sensitive human consequences may be to variations in the social future.
But long-term forecasting is still a very inexact practice. The near-term research agenda should emphasize processes of human response to the stresses that global environmental change might present.
People may respond to experienced or anticipated global change by intervening at any point in the cycle of interaction between human and environmental systems. Mitigation—that is, actions that alter environmental systems to prevent, limit, delay, or slow the rate of undesired global changes—may involve direct interventions in the environment, direct interventions in the human proximate causes, or indirect interventions in the driving forces of global change. People can also respond by blocking the undesired proximate effects of environmental systems on what they what is your lifes blueprint, for example, by applying sunscreens to the skin to help prevent cancer from exposure to ultraviolet radiation.
They can make adjustments that prevent or compensate for imminent or manifest losses of welfare from what is global environmental change change, for example, famine relief or drought insurance. And people can intervene to improve the robustness of social systems by altering them so that an unchecked environmental change would produce less reduction of values than would otherwise be the case.
For example, crop polyculture may not slow the pace of global change, but it is more robust than monoculture in the face of drought, acid deposition, and ozone depletion.
If crop failure occurs, it will affect only some crops, making famine less likely. Many of these responses may indirectly affect the driving forces of global change.
Consequently, the what does cover letter means in a resume agenda should include studies of both the direct and secondary effects of responses to global change, using the best available methods of evaluation research.
Global change is likely to engender conflict—about whether it is in fact occurring, whether any organized response is necessary, whether response should emphasize mitigation or not, who should pay the costs, and who environmenyal the right to decide. Such conflicts tend to persist because they are based in part on differing inter. The research agenda should include efforts environ,ental clarify the connections between particular environmental changes and particular types of conflict.
Environmetal should also include increased efforts to test the efficacy of different techniques and institutions for resolving or managing environmental conflicts. Human responses to global change occur within seven interacting systems. Within each system, there are significant areas of knowledge and important unanswered questions; in addition, much remains to be learned about how the systems combine to determine the global human response. Individual perception, judgment, and action are important because all decisions are based on inputs from individuals; because individual actions, in the aggregate, often have major effects; and because individuals can be organized environmenta, influence collective and political responses.
Markets are important because global change is likely to affect the prices of important commodities and factors of economic production. However, existing markets do not provide the right price signals for managing global change for various reasons, and the participants in markets do not always follow strict rules of economic rationality.
Sociocultural systemsincluding families, clans, tribes, and communities held together by such bonds as solidarity, obligation, duty, and love sometimes develop ways of interacting with their environments for instance, some systems of agroforestry that may be widely adaptable as strategies for response.
Their informal social bonds can also affect individual and community responses to global change and to policy. Organized responses at the subnational levelsuch as by communities, social movements, and corporations and trade associations, can be significant both in their own right and by influencing the adoption and implementation of government policies.
Chaange policies are critical in the human response to global change by making possible international agreements and by affecting the ability to respond at local and individual wuat. Not only environmental policy, but also macroeconomic, fiscal, agricultural, and science and technology policies are important. International cooperation is necessary to address some large-scale environmental changes such as ozone depletion and global warming. The formation of international institutions for response to global change is widely considered to be the key to solving.
Global social changesuch as the expansion of the global market; the worldwide spread of communication networks, democratic political forms, and scientific knowledge; and the global resurgence of cultural identity as a social force may influence the way humanity responds to the gpobal of global change and its ability to adapt to experienced change.
The research agenda should include studies of responses within each of these systems, especially comparative studies of how the systems operate in different spatial and temporal contexts. Because systems of human response are golbal affected by each other, a high priority should be given to studies linking response systems to each other and short-term effects to long-term ones.
The study of human interactions with the global environment poses difficult problems of theory and method that will require new links among disciplines, theoretical constructs to deal with whqt complexities and the large spatial and temporal scales, and careful selection of research cchange. Interdisciplinary collaboration is essential. A high priority of the human environmenta research effort should be to support problem-centered interaction among social and natural scientists, for example through research projects that require such contact, problem-focused scholarly meetings, and interdisciplinary research centers.
New theoretical tools are required. Studies of what is global environmental change human dimensions of global change require analysis at spatial and temporal expanses much greater than most social scientific theory encompasses. Social qhat will need to develop new theoretical tools for analyzing such issues as major national and international changes in political-economic structure, the envidonmental of variation and change in slowly changing aspects of human systems, the long-term impacts of short-term social changes, relationships between global social changes and the global environment, and links between human-environment relationships at different levels of environnental aggregation.
Analyses of these general problems in the global change context may lead to important theoretical advances of general use in social science. Methodological pluralism is the most appropriate strategy. At least for the near-term, a strong emphasis on building integrative models is premature for studying the human globql.
For the human interactions research agenda, much more understanding of the underlying processes needs to be developed before great strides can be made in integrative modeling. Formal modeling should participate in a dialogue of what is a feudal society, with several complementary methods being used to give a more complete picture than any single method can produce.
Post hoc analyses are essential for evaluating human responses. There remains no substitute for empirical analysis of outcomes after the fact. Post hoc evaluations are an important part of the process of analyzing policy alternatives for response to global change, and resources should be provided for them. In particular, federal agencies with programs or policies anticipated to affect processes of global environmental change should routinely budget funds for evaluation studies of the intended and unintended consequences of these activities.
Unlike the practice of preparing environmental impact statements, this recommendation concerns data gathering after a policy is in place. A strong research program on the human dimensions of global change requires improved availability of and access to existing data, quality control, and collection of critical new data.
Data Availability Data exist in great quantity on social, economic, demographic, and political variables relevant to the human dimensions of global change, and in even greater quantity on relevant nonhuman variables. The major need at this point is for governmental and private support for the necessary infrastructure for publicly shared data on demographic, economic, political, attitudinal, and natural or physical changes. This particularly includes the one-time costs of creating a network and archival facility to make the material accessible to researchers and to make data on social and natural phenomena mutually intelligible.
The network should include measures of the major driving forces of global change at the lowest available level of aggregation. We emphasize that expenditures on such a system should not jeopardize needed resources for doing research and understanding the data. The U. The federal government should support an effort to validate what caused the fall of the ottoman empire most promising remotely sensed indicators of social phenomena and include them in the information network.
The committee recommends that social scientists, representing a variety of disciplines, be involved at every stage of the design and implementation of national data and information systems relevant to the human dimensions of global change, including representation on the Earth Observing System Science Advisory Panel, to ensure that data are collected and archived in a form that facilitates analyzing human interactions.
Quality and Interpretability of Data The quality of existing data relevant to the human dimensions of global change may be doubtful because of errors in collection, problems of sampling and coverage, problems of estimation, incompatibility between ground-based and remotely sensed data, problems of aggregation, insufficient attention to methodology, or a lack of uniform definitions of variables across data-collection what is global environmental change. The prevalence of these problems suggests the importance of research on the quality of available data sets.
Understanding Global Change Visit this page for a guided tour of the Understanding Global Change Framework and the fundamental Earth system processes relevant to environmental and climate change. Understanding Global Change Infographic Use the UGC Infographic to navigate to content about global change processes and phenomena. Explore global change topics on the content . Global Environmental Change offers a strategy for combining the efforts of natural and social scientists to better understand how our actions influence global change and how global change influences us. The volume is accessible to the nonscientist and provides a . The planet is facing extraordinary challenges; among them are climate change, loss of biodiversity, environmental degradation, and the unequal distribution of critical resources. Indeed, the environmental challenges that the world now faces have never been more complex, posing greater threat to people around the globe.
The potential future effects of global climate change include more frequent wildfires, longer periods of drought in some regions and an increase in the number, duration and intensity of tropical storms. Global climate change has already had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.
Effects that scientists had predicted in the past would result from global climate change are now occurring: loss of sea ice, accelerated sea level rise and longer, more intense heat waves.
Scientists have high confidence that global temperatures will continue to rise for decades to come, largely due to greenhouse gases produced by human activities. According to the IPCC, the extent of climate change effects on individual regions will vary over time and with the ability of different societal and environmental systems to mitigate or adapt to change.
The IPCC predicts that increases in global mean temperature of less than 1. Net annual costs will increase over time as global temperatures increase. Some of the long-term effects of global climate change in the United States are as follows, according to the Third and Fourth National Climate Assessment Reports:. Global climate is projected to continue to change over this century and beyond. Go backward and forward in time with this interactive visualization that illustrates how the Earth's climate has changed in recent history.
Because human-induced warming is superimposed on a naturally varying climate, the temperature rise has not been, and will not be, uniform or smooth across the country or over time. The length of the frost-free season and the corresponding growing season has been increasing nationally since the s, with the largest increases occurring in the western United States, affecting ecosystems and agriculture. Across the United States, the growing season is projected to continue to lengthen.
In a future in which heat-trapping gas emissions continue to grow, increases of a month or more in the lengths of the frost-free and growing seasons are projected across most of the U. The largest increases in the frost-free season more than eight weeks are projected for the western U. The increases will be considerably smaller if heat-trapping gas emissions are reduced.
This NASA visualization presents observational evidence that the growing season climatological spring is occurring earlier in the Northern Hemisphere. Average U. More winter and spring precipitation is projected for the northern United States, and less for the Southwest, over this century. Projections of future climate over the U. This trend is projected to occur even in regions where total precipitation is expected to decrease, such as the Southwest.
These NASA visualizations show model projections of the precipitation changes from to as a percentage difference between the year precipitation averages and the average.
The official website for NASA's fleet of Earth science missions that study rainfall and other types precipitation around the globe. How much do you know about Earth's water cycle and the crucial role it plays in our climate? Droughts in the Southwest and heat waves periods of abnormally hot weather lasting days to weeks everywhere are projected to become more intense, and cold waves less intense everywhere.
Summer temperatures are projected to continue rising, and a reduction of soil moisture, which exacerbates heat waves, is projected for much of the western and central U. By the end of this century, what have been once-inyear extreme heat days one-day events are projected to occur every two or three years over most of the nation. Droughts in the Southwest and Central Plains of the United States in the second half of the 21st century could be drier and longer than anything humans have seen in those regions in the last 1, years, according to a NASA study published in Science Advances on February 12, The intensity, frequency and duration of North Atlantic hurricanes, as well as the frequency of the strongest Category 4 and 5 hurricanes, have all increased since the early s.
The relative contributions of human and natural causes to these increases are still uncertain. Hurricane-associated storm intensity and rainfall rates are projected to increase as the climate continues to warm.
This video explains the findings of this study. Global sea level has risen by about 8 inches since reliable record keeping began in It is projected to rise another 1 to 8 feet by This is the result of added water from melting land ice and the expansion of seawater as it warms. In the next several decades, storm surges and high tides could combine with sea level rise and land subsidence to further increase flooding in many regions.
Ocean waters will therefore continue to warm and sea level will continue to rise for many centuries at rates equal to or higher than those of the current century. An indicator of changes in the Arctic sea ice minimum over time. Arctic sea ice extent both affects and is affected by global climate change. An interactive exploration of how global warming is affecting sea ice, glaciers and continental ice sheets worldwide.
Below are some of the impacts that are currently visible throughout the U. Global Change Research Program :. Heat waves, heavy downpours and sea level rise pose growing challenges to many aspects of life in the Northeast.
Infrastructure, agriculture, fisheries and ecosystems will be increasingly compromised. Many states and cities are beginning to incorporate climate change into their planning. Changes in the timing of streamflow reduce water supplies for competing demands. Sea level rise, erosion, inundation, risks to infrastructure and increasing ocean acidity pose major threats. Increasing wildfire, insect outbreaks and tree diseases are causing widespread tree die-off. Extreme heat will affect health, energy, agriculture and more.
Decreased water availability will have economic and environmental impacts. Extreme heat, heavy downpours and flooding will affect infrastructure, health, agriculture, forestry, transportation, air and water quality, and more. Climate change will also exacerbate a range of risks to the Great Lakes. Increased heat, drought and insect outbreaks, all linked to climate change, have increased wildfires.
Declining water supplies, reduced agricultural yields, health impacts in cities due to heat, and flooding and erosion in coastal areas are additional concerns. Taken as a whole, the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time. An indicator of current global sea level as measured by satellites; updated monthly. GISS climate models.
Climate Time Machine. Video: Global warming from to NASA visualization of future global temperature projections based on current climate models. Visualization comparing s and s. NASA visualizations of future precipitation scenarios. Precipitation Measurement Missions. Precipitation quiz. West projected to be worst of millennium. Sea level quiz.
Test your knowledge of sea level rise and its effect on global populations. The Arctic Ocean is expected to become essentially ice free in summer before mid-century. Global Ice Viewer. Images of Change. Explore a stunning gallery of before-and-after images of Earth from land and space that reveal our home planet in a state of flux.
Climate Mobile Apps. Keep track of Earth's vital signs, see the planet in a state of flux and slow the pace of global warming with NASA's free mobile apps. Travel through Earth's recent climate history and see how increasing carbon dioxide, global temperature and sea ice have changed over time.
Eyes on the Earth. Earth's ice cover is shrinking. See how climate change has affected glaciers, sea ice, and continental ice sheets.