Query: policies based on previous climate model output and predictions might need to be reconsidered

Relevant passages:
Sensitivity analysis <=SEP=> Sensitivity analysis is the study of how the uncertainty in the output of a mathematical model or system ( numerical or otherwise ) can be apportioned to different sources of uncertainty in its inputs . A related practice is uncertainty analysis , which has a greater focus on uncertainty quantification and propagation of uncertainty ; ideally , uncertainty and sensitivity analysis should be run in tandem .   The process of recalculating outcomes under alternative assumptions to determine the impact of a variable under sensitivity analysis can be useful for a range of purposes , including :  Testing the robustness of the results of a model or system in the presence of uncertainty .  Increased understanding of the relationships between input and output variables in a system or model .  Uncertainty reduction , through the identification of model inputs that cause significant uncertainty in the output and should therefore be the focus of attention in order to increase robustness ( perhaps by further research ) .  Searching for errors in the model ( by encountering unexpected relationships between inputs and outputs ) .  Model simplification -- fixing model inputs that have no effect on the output , or identifying and removing redundant parts of the model structure .  Enhancing communication from modelers to decision makers ( e.g. by making recommendations more credible , understandable , compelling or persuasive ) .  Finding regions in the space of input factors for which the model output is either maximum or minimum or meets some optimum criterion ( see optimization and Monte Carlo filtering ) .  In case of calibrating models with large number of parameters , a primary sensitivity test can ease the calibration stage by focusing on the sensitive parameters . Not knowing the sensitivity of parameters can result in time being uselessly spent on non-sensitive ones .  To seek to identify important connections between observations , model inputs , and predictions or forecasts , leading to the development of better models .

Science <=SEP=> Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe .   Contemporary science is typically subdivided into the natural sciences , which study the material universe ; the social sciences , which study people and societies ; and the formal sciences , which study logic and mathematics . The formal sciences are often excluded as they do not depend on empirical observations . Disciplines which use science , like engineering and medicine , may also be considered to be applied sciences .   From classical antiquity through the 19th century , science as a type of knowledge was more closely linked to philosophy than it is now , and in the Western world the term `` natural philosophy '' once encompassed fields of study that are today associated with science , such as astronomy , medicine , and physics . However , during the Islamic Golden Age foundations for the scientific method were laid by Ibn al-Haytham in his Book of Optics . While the classification of the material world by the ancient Indians and Greeks into air , earth , fire and water was more philosophical , medieval Middle Easterns used practical and experimental observation to classify materials .   In the 17th and 18th centuries , scientists increasingly sought to formulate knowledge in terms of physical laws . Over the course of the 19th century , the word `` science '' became increasingly associated with the scientific method itself as a disciplined way to study the natural world . It was during this time that scientific disciplines such as biology , chemistry , and physics reached their modern shapes . That same time period also included the origin of the terms `` scientist '' and `` scientific community '' , the founding of scientific institutions , and the increasing significance of their interactions with society and other aspects of culture .

General circulation model <=SEP=> A general circulation model ( GCM ) is a type of climate model . It employs a mathematical model of the general circulation of a planetary atmosphere or ocean . It uses the Navier -- Stokes equations on a rotating sphere with thermodynamic terms for various energy sources ( radiation , latent heat ) . These equations are the basis for computer programs used to simulate the Earth 's atmosphere or oceans . Atmospheric and oceanic GCMs ( AGCM and OGCM ) are key components along with sea ice and land-surface components .   GCMs and global climate models are used for weather forecasting , understanding the climate and forecasting climate change .   Versions designed for decade to century time scale climate applications were originally created by Syukuro Manabe and Kirk Bryan at the Geophysical Fluid Dynamics Laboratory in Princeton , New Jersey . These models are based on the integration of a variety of fluid dynamical , chemical and sometimes biological equations .

Global warming <=SEP=> Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years .   In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing .   Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years .   Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) ,  whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change .   Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned .