Query: Humans are too insignificant to affect global climate.

Relevant passages:
Holocene extinction <=SEP=> The Holocene extinction , otherwise referred to as the Sixth extinction or Anthropocene extinction , is the ongoing extinction event of species during the present Holocene epoch , mainly due to human activity . The large number of extinctions spans numerous families of plants and animals , including mammals , birds , amphibians , reptiles and arthropods . With widespread degradation of highly biodiverse habitats such as coral reefs and rainforest , as well as other areas , the vast majority of these extinctions is thought to be undocumented . According to the species-area theory , and based on upper-bound estimating , the present rate of extinction may be up to 140,000 species per year , making it the greatest loss of biodiversity since the Cretaceous -- Paleogene extinction event .   The Holocene extinction includes the disappearance of large land animals known as megafauna , starting at the end of the last Ice Age . Megafauna outside of the African continent , which did not evolve alongside humans , proved highly sensitive to the introduction of new predation , and many died out shortly after early humans began spreading and hunting across the Earth ( additionally , many African species have also gone extinct in the Holocene ) . These extinctions , occurring near the Pleistocene -- Holocene boundary , are sometimes referred to as the Quaternary extinction event .   The arrival of humans on different continents coincides with megafaunal extinction . The most popular theory is that human overhunting of species added to existing stress conditions . Although there is debate regarding how much human predation affected their decline , certain population declines have been directly correlated with human activity , such as the extinction events of New Zealand and Hawaii . Aside from humans , climate change may have been a driving factor in the megafaunal extinctions , especially at the end of the Quaternary .   The ecology of humanity has been noted as being that of an unprecedented `` global superpredator '' that regularly preys on the adults of other apex predators and has worldwide effects on food webs . Extinctions of species have occurred on every land mass and ocean , with many famous examples within Africa , Asia , Europe , Australia , North and South America , and on smaller islands . Overall , the Holocene extinction can be characterized by the human impact on the environment . The Holocene extinction continues into the 21st century , with meat consumption , overfishing , ocean acidification and the amphibian crisis being a few broader examples of an almost universal , cosmopolitan decline in biodiversity . A ballooning human population along with profligate consumption are considered to be the primary drivers of this rapid decline .

Human impact on the environment <=SEP=> Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments , biodiversity , and other resources . The term anthropogenic designates an effect or object resulting from human activity . The term was first used in the technical sense by Russian geologist Alexey Pavlov , and was first used in English by British ecologist Arthur Tansley in reference to human influences on climax plant communities . The atmospheric scientist Paul Crutzen introduced the term `` Anthropocene '' in the mid-1970s . The term is sometimes used in the context of pollution emissions that are produced as a result of human activities but applies broadly to all major human impacts on the environment .

Human <=SEP=> Modern humans ( Homo sapiens , primarily ssp . Homo sapiens sapiens ) are the only extant members of Hominina tribe ( or human tribe ) , a branch of the tribe Hominini belonging to the family of great apes . They are characterized by erect posture and bipedal locomotion ; high manual dexterity and heavy tool use compared to other animals ; and a general trend toward larger , more complex brains and societies .   Early hominins -- particularly the australopithecines , whose brains and anatomy are in many ways more similar to ancestral non-human apes -- are less often referred to as `` human '' than hominins of the genus Homo . Several of these hominins used fire , occupied much of Eurasia , and gave rise to anatomically modern Homo sapiens in Africa about 200,000 years ago . They began to exhibit evidence of behavioral modernity around 50,000 years ago . In several waves of migration , anatomically modern humans ventured out of Africa and populated most of the world .   The spread of humans and their large and increasing population has had a profound impact on large areas of the environment and millions of native species worldwide . Advantages that explain this evolutionary success include a relatively larger brain with a particularly well-developed neocortex , prefrontal cortex and temporal lobes , which enable high levels of abstract reasoning , language , problem solving , sociality , and culture through social learning . Humans use tools to a much higher degree than any other animal , are the only extant species known to build fires and cook their food , and are the only extant species to clothe themselves and create and use numerous other technologies and arts .   Humans are uniquely adept at utilizing systems of symbolic communication ( such as language and art ) for self-expression and the exchange of ideas , and for organizing themselves into purposeful groups . Humans create complex social structures composed of many cooperating and competing groups , from families and kinship networks to political states . Social interactions between humans have established an extremely wide variety of values , social norms , and rituals , which together form the basis of human society . Curiosity and the human desire to understand and influence the environment and to explain and manipulate phenomena ( or events ) has provided the foundation for developing science , philosophy , mythology , religion , anthropology , and numerous other fields of knowledge .   Though most of human existence has been sustained by hunting and gathering in band societies , increasing numbers of human societies began to practice sedentary agriculture approximately some 10,000 years ago , domesticating plants and animals , thus allowing for the growth of civilization . These human societies subsequently expanded in size , establishing various forms of government , religion , and culture around the world , unifying people within regions to form states and empires . The rapid advancement of scientific and medical understanding in the 19th and 20th centuries led to the development of fuel-driven technologies and increased lifespans , causing the human population to rise exponentially . Today the global human population is estimated by the United Nations to be near billion .

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 .