Query: Their analysis calculates the existential climate-related security risk to Earth through a scenario set 30 years into the future.

Relevant passages:
Future of Earth <=SEP=> The biological and geological future of Earth can be extrapolated based upon the estimated effects of several long-term influences . These include the chemistry at Earth 's surface , the rate of cooling of the planet 's interior , the gravitational interactions with other objects in the Solar System , and a steady increase in the Sun 's luminosity . An uncertain factor in this extrapolation is the ongoing influence of technology introduced by humans , such as climate engineering , which could cause significant changes to the planet . The current Holocene extinction is being caused by technology and the effects may last for up to five million years . In turn , technology may result in the extinction of humanity , leaving the planet to gradually return to a slower evolutionary pace resulting solely from long-term natural processes .   Over time intervals of hundreds of millions of years , random celestial events pose a global risk to the biosphere , which can result in mass extinctions . These include impacts by comets or asteroids with diameters of 5 -- or more , and the possibility of a massive stellar explosion , called a supernova , within a 100-light-year radius of the Sun , called a Near-Earth supernova . Other large-scale geological events are more predictable . If the long-term effects of global warming are disregarded , Milankovitch theory predicts that the planet will continue to undergo glacial periods at least until the Quaternary glaciation comes to an end . These periods are caused by variations in eccentricity , axial tilt , and precession of the Earth 's orbit . As part of the ongoing supercontinent cycle , plate tectonics will probably result in a supercontinent in 250 -- 350 million years . Some time in the next 1.5 -- 4.5 billion years , the axial tilt of the Earth may begin to undergo chaotic variations , with changes in the axial tilt of up to 90 ° .   During the next four billion years , the luminosity of the Sun will steadily increase , resulting in a rise in the solar radiation reaching the Earth . This will result in a higher rate of weathering of silicate minerals , which will cause a decrease in the level of carbon dioxide in the atmosphere . In about 600 million years from now , the level of CO2 will fall below the level needed to sustain C3 carbon fixation photosynthesis used by trees . Some plants use the C4 carbon fixation method , allowing them to persist at concentrations as low as 10 parts per million . However , the long-term trend is for plant life to die off altogether . The extinction of plants will be the demise of almost all animal life , since plants are the base of the food chain on Earth .   In about one billion years , the solar luminosity will be 10 % higher than at present . This will cause the atmosphere to become a `` moist greenhouse '' , resulting in a runaway evaporation of the oceans . As a likely consequence , plate tectonics will come to an end , and with them the entire carbon cycle . Following this event , in about 2 − 3 billion years , the planet 's magnetic dynamo may cease , causing the magnetosphere to decay and leading to an accelerated loss of volatiles from the outer atmosphere . Four billion years from now , the increase in the Earth 's surface temperature will cause a runaway greenhouse effect , heating the surface enough to melt it . By that point , all life on the Earth will be extinct . The most probable fate of the planet is absorption by the Sun in about 7.5 billion years , after the star has entered the red giant phase and expanded to cross the planet 's current orbit .

Global catastrophic risk <=SEP=> A global catastrophic risk is a hypothetical future event that has the potential to damage human well-being on a global scale . Some events could cripple or destroy modern civilization . Any event that could cause human extinction is known as an existential risk .   Potential global catastrophic risks include anthropogenic risks ( technology risks , governance risks ) and natural or external risks . Examples of technology risks are hostile artificial intelligence , biotechnology risks , or nanotechnology weapons . Insufficient global governance creates risks in the social and political domain ( potentially leading to a global war with or without a nuclear holocaust , bioterrorism using genetically modified organisms , cyberterrorism destroying critical infrastructures like the electrical grid , or the failure to manage a natural pandemic ) as well as problems and risks in the domain of earth system governance ( with risks resulting from global warming , environmental degradation , mineral resource exhaustion , fossil energy exhaustion , or famine as a result of non-equitable resource distribution , human overpopulation , crop failures and non-sustainable agriculture ) . Examples for non-anthropogenic risks are an asteroid impact event , a supervolcanic eruption , a lethal gamma-ray burst , a geomagnetic storm destroying all electronic equipment , natural long-term climate change , or extraterrestrial life impacting life on Earth .

Environmental sociology <=SEP=> Environmental sociology is typically defined as the sociological study of societal-environmental interactions , although this definition immediately presents the problem of integrating human cultures with the rest of the environment . Although the focus of the field is the relationship between society and environment in general , environmental sociologists typically place special emphasis on studying the social factors that cause environmental problems , the societal impacts of those problems , and efforts to solve the problems . In addition , considerable attention is paid to the social processes by which certain environmental conditions become socially defined as problems .   Although there was sometimes acrimonious debate between the constructivist and realist `` camps '' within environmental sociology in the 1990s , the two sides have found considerable common ground as both increasingly accept that while most environmental problems have a material reality they nonetheless become known only via human processes such as scientific knowledge , activists ' efforts , and media attention . In other words , most environmental problems have a real ontological status despite our knowledge/awareness of them stemming from social processes , processes by which various conditions are constructed as problems by scientists , activists , media and other social actors . Correspondingly , environmental problems must all be understood via social processes , despite any material basis they may have external to humans . This interactiveness is now broadly accepted , but many aspects of the debate continue in contemporary research in the field .

Global issue <=SEP=> Informally , a global issue describes any social , economic , political or environmental problem that affects the global community , possibly in a catastrophic way .   Solution to global issues requires cooperation among nations .   In their book Global Issues , Hite and Seitz emphasize that global issues are qualitatively different from international affairs and that the former arise from growing international interdependencies which makes the issues themselves interdependent .