Query: 'To suddenly label CO2 as a "pollutant" is a disservice to a gas that has played an enormous role in the development and sustainability of all life on this wonderful Earth.

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Climate change mitigation <=SEP=> Climate change mitigation consists of actions to limit the magnitude or rate of long-term climate change . Climate change mitigation generally involves reductions in human ( anthropogenic ) emissions of greenhouse gases ( GHGs ) . Mitigation may also be achieved by increasing the capacity of carbon sinks , e.g. , through reforestation . Mitigation policies can substantially reduce the risks associated with human-induced global warming .   According to the IPCC 's 2014 assessment report , `` Mitigation is a public good ; climate change is a case of the ` tragedy of the commons . Effective climate change mitigation will not be achieved if each agent ( individual , institution or country ) acts independently in its own selfish interest ( see international cooperation and emissions trading ) , suggesting the need for collective action . Some adaptation actions , on the other hand , have characteristics of a private good as benefits of actions may accrue more directly to the individuals , regions , or countries that undertake them , at least in the short term . Nevertheless , financing such adaptive activities remains an issue , particularly for poor individuals and countries . ''   Examples of mitigation include phasing out fossil fuels by switching to low-carbon energy sources , such as renewable and nuclear energy , and expanding forests and other `` sinks '' to remove greater amounts of carbon dioxide from the atmosphere . Energy efficiency may also play a role , for example , through improving the insulation of buildings . Another approach to climate change mitigation is climate engineering .   Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) . The ultimate objective of the UNFCCC is to stabilize atmospheric concentrations of GHGs at a level that would prevent dangerous human interference of the climate system . Scientific analysis can provide information on the impacts of climate change , but deciding which impacts are dangerous requires value judgments .   In 2010 , Parties to the UNFCCC agreed that future global warming should be limited to below 2.0 ° C ( 3.6 ° F ) relative to the pre-industrial level . With the Paris Agreement of 2015 this was confirmed , but was revised with a new target laying down `` parties will do the best '' to achieve warming below 1.5 ° C . The current trajectory of global greenhouse gas emissions does not appear to be consistent with limiting global warming to below 1.5 or 2 ° C . Other mitigation policies have been proposed , some of which are more stringent or modest than the 2 ° C limit .

Emissions trading <=SEP=> Emissions trading or cap and trade is a government-mandated , market-based approach to controlling pollution by providing economic incentives for achieving reductions in the emissions of pollutants . In contrast to command-and-control environmental regulations such as best available technology ( BAT ) standards and government subsidies , cap and trade ( CAT ) schemes are a type of flexible environmental regulation that allows organizations to decide how best to meet policy targets . Various countries , states and groups of companies have adopted such trading systems , notably for mitigating climate change .   A central authority ( usually a governmental body ) allocates or sells a limited number of permits to discharge specific quantities of a specific pollutant per time period . Polluters are required to hold permits in amount equal to their emissions . Polluters that want to increase their emissions must buy permits from others willing to sell them . Financial derivatives of permits can also be traded on secondary markets .   In theory , polluters who can reduce emissions most cheaply will do so , achieving the emission reduction at the lowest cost to society . Cap and trade is meant to provide the private sector with the flexibility required to reduce emissions while stimulating technological innovation and economic growth .   There are active trading programs in several air pollutants . For greenhouse gases , which cause climate change , permit units are often called carbon credits . The largest greenhouse gases trading program is the European Union Emission Trading Scheme , which trades primarily in European Union Allowances ( EUAs ) ; the Californian scheme trades in California Carbon Allowances , the New Zealand scheme in New Zealand Units and the Australian scheme in Australian Units . The United States has a national market to reduce acid rain and several regional markets in nitrogen oxides .

Sustainable energy <=SEP=> Sustainable energy is energy that is consumed at insignificant rates compared to its supply and with manageable collateral effects , especially environmental effects . Another common definition of sustainable energy is an energy system that serves the needs of the present without compromising the ability of future generations to meet their needs . The organizing principle for sustainability is sustainable development , which includes the four interconnected domains : ecology , economics , politics and culture . Sustainability science is the study of sustainable development and environmental science .   Technologies promote sustainable energy including renewable energy sources , such as hydroelectricity , solar energy , wind energy , wave power , geothermal energy , bioenergy , tidal power and also technologies designed to improve energy efficiency . Costs have fallen dramatically in recent years , and continue to fall . Most of these technologies are either economically competitive or close to being so . Increasingly , effective government policies support investor confidence and these markets are expanding . Considerable progress is being made in the energy transition from fossil fuels to ecologically sustainable systems , to the point where many studies support 100 % renewable energy .

Urbanization <=SEP=> Urbanization refers to the population shift from rural to urban areas , `` the gradual increase in the proportion of people living in urban areas '' , and the ways in which each society adapts to the change . It is predominantly the process by which towns and cities are formed and become larger as more people begin living and working in central areas . The United Nations projected that half of the world 's population would live in urban areas at the end of 2008 . It is predicted that by 2050 about 64 % of the developing world and 86 % of the developed world will be urbanized . That is equivalent to approximately 3 billion urbanites by 2050 , much of which will occur in Africa and Asia . Notably , the United Nations has also recently projected that nearly all global population growth from 2017 to 2030 will be absorbed by cities , about 1.1 billion new urbanites over the next 13 years .   Urbanization is relevant to a range of disciplines , including geography , sociology , economics , urban planning and public health . The phenomenon has been closely linked to modernization , industrialization and the sociological process of rationalization . Urbanization can be seen as a specific condition at a set time ( e.g. the proportion of total population or area in cities or towns ) or as an increase in that condition over time . So urbanization can be quantified either in terms of , say , the level of urban development relative to the overall population , or as the rate at which the urban proportion of the population is increasing . Urbanization creates enormous social , economic and environmental changes , which provide an opportunity for sustainability with the `` potential to use resources more efficiently , to create more sustainable land use and to protect the biodiversity of natural ecosystems . ''   Urbanization is not merely a modern phenomenon , but a rapid and historic transformation of human social roots on a global scale , whereby predominantly rural culture is being rapidly replaced by predominantly urban culture . The first major change in settlement patterns was the accumulation of hunter-gatherers into villages many thousand years ago . Village culture is characterized by common bloodlines , intimate relationships and communal behavior whereas urban culture is characterized by distant bloodlines , unfamiliar relations and competitive behavior . This unprecedented movement of people is forecast to continue and intensify during the next few decades , mushrooming cities to sizes unthinkable only a century ago .   Today , in Asia the urban agglomerations of Osaka , Karachi , Jakarta , Mumbai , Shanghai , Manila , Seoul and Beijing are each already home to over 20 million people , while Delhi and Tokyo are forecast to approach or exceed 40 million people each within the coming decade . Outside Asia , Mexico City , São Paulo , London , New York City , Istanbul , Lagos and Cairo are , or soon will be , home to over 10 million people .

Sustainability <=SEP=> In ecology , sustainability ( from sustain and ability ) is the property of biological systems to remain diverse and productive indefinite #Adjective . Long-lived and healthy wetlands and forests are examples of sustainable biological systems . In more general terms , sustainability is the endurance of systems and processes . The organizing principle for sustainability is sustainable development , which includes the four interconnected domains : ecology , economics , politics and culture . Sustainability science is the study of sustainable development and environmental science .   Sustainability can also be defined as a socio-ecological process characterized by the pursuit of a common ideal .  An ideal is by definition unattainable in a given time and space . However , by persistently and dynamically approaching it , the process results in a sustainable system .   Healthy ecosystems and environments are necessary to the survival of humans and other organisms . Ways of reducing negative human impact are environmentally-friendly chemical engineering , environmental resources management and environmental protection . Information is gained from green chemistry , earth science , environmental science and conservation biology . Ecological economics studies the fields of academic research that aim to address human economies and natural ecosystems .   Moving towards sustainability is also a social challenge that entails international and national law , urban planning and transport , local and individual lifestyles and ethical consumerism . Ways of living more sustainably can take many forms from reorganizing living conditions ( e.g. , ecovillages , eco-municipalities and sustainable cities ) , reappraising economic sectors ( permaculture , green building , sustainable agriculture ) , or work practices ( sustainable architecture ) , using science to develop new technologies ( green technologies , renewable energy and sustainable fission and fusion power ) , or designing systems in a flexible and reversible manner , and adjusting individual lifestyles that conserve natural resources .   `` The term ` sustainability ' should be viewed as humanity 's target goal of human-ecosystem equilibrium ( homeostasis ) , while ` sustainable development ' refers to the holistic approach and temporal processes that lead us to the end point of sustainability . '' ( 305 ) Despite the increased popularity of the use of the term `` sustainability '' , the possibility that human societies will achieve environmental sustainability has been , and continues to be , questioned -- in light of environmental degradation , climate change , overconsumption , population growth and societies ' pursuit of unlimited economic growth in a closed system .