Query: Extreme weather events are being made more frequent and worse by global warming.

Relevant passages:
Weather <=SEP=> Weather is the state of the atmosphere , to the degree that it is hot or cold , wet or dry , calm or stormy , clear or cloudy . Most weather phenomena occur in the lowest level of the atmosphere , the troposphere , just below the stratosphere . Weather refers to day-to-day temperature and precipitation activity , whereas climate is the term for the averaging of atmospheric conditions over longer periods of time . When used without qualification , `` weather '' is generally understood to mean the weather of Earth .   Weather is driven by air pressure , temperature and moisture differences between one place and another . These differences can occur due to the sun 's angle at any particular spot , which varies with latitude . The strong temperature contrast between polar and tropical air gives rise to the largest scale atmospheric circulations : the Hadley Cell , the Ferrel Cell , the Polar Cell , and the jet stream . Weather systems in the mid-latitudes , such as extratropical cyclones , are caused by instabilities of the jet stream flow . Because the Earth 's axis is tilted relative to its orbital plane , sunlight is incident at different angles at different times of the year . On Earth 's surface , temperatures usually range ± 40 ° C ( − 40 ° F to 100 ° F ) annually . Over thousands of years , changes in Earth 's orbit can affect the amount and distribution of solar energy received by the Earth , thus influencing long-term climate and global climate change .   Surface temperature differences in turn cause pressure differences . Higher altitudes are cooler than lower altitudes as most atmospheric heating is due to contact with the Earth 's surface while radiative losses to space are mostly constant . Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location . The Earth 's weather system is a chaotic system ; as a result , small changes to one part of the system can grow to have large effects on the system as a whole . Human attempts to control the weather have occurred throughout history , and there is evidence that human activities such as agriculture and industry have modified weather patterns .   Studying how the weather works on other planets has been helpful in understanding how weather works on Earth . A famous landmark in the Solar System , Jupiter 's Great Red Spot , is an anticyclonic storm known to have existed for at least 300 years . However , weather is not limited to planetary bodies . A star 's corona is constantly being lost to space , creating what is essentially a very thin atmosphere throughout the Solar System . The movement of mass ejected from the Sun is known as the solar wind .

Heat wave <=SEP=> A heat wave is a prolonged period of excessively hot weather , which may be accompanied by high humidity , especially in oceanic climate countries . While definitions vary , a heat wave is measured relative to the usual weather in the area and relative to normal temperatures for the season . Temperatures that people from a hotter climate consider normal can be termed a heat wave in a cooler area if they are outside the normal climate pattern for that area .   The term is applied both to hot weather variations and to extraordinary spells of hot which may occur only once a century . Severe heat waves have caused catastrophic crop failures , thousands of deaths from hyperthermia , and widespread power outages due to increased use of air conditioning . A heat wave is considered extreme weather , and a danger because heat and sunlight may overheat the human body .

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 .

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 .