Hello. I'm posting this because i'm sick of all the lies that some people try to put out in order to generate doubt that AGW exist. Because of that i'll put some reasons on why human-caused climate change exists and discredit some of the conspiracy theories behind the deniers (and i personally think that putting denial links should be treated as conspiracy theory on these forums).
Bear in mind that some of the evidence complements eachother. so its desirable to read all of them.
Before this starts, you should read these links on what does greenhouse gas means, and how does the sun... well heats things
https://en.wikipedia.org/wiki/Greenhouse_gas
http://www.c2es.org/facts-figures/main-ghgs
https://www.reference.com/science/su...014b7e2f6f84e7
http://science.howstuffworks.com/star.htm
First evidence: Carbon (and Methane) has been proven to be a greenhouse gas, or to be more exact, a heat trapping gas. There's even a video on mythbusters that prove it, on a controlled condition. Most of the solar radiation that reaches our planet is on the infrared to visible spectrum.
https://scied.ucar.edu/carbon-dioxid...ared-radiation
https://www.youtube.com/watch?v=pPRd5GT0v0I
https://www.youtube.com/watch?v=bX4eOg2LaSY
http://naturalfrequency.com/wiki/solar-radiation
Second Evidence: Carbon has been trapped since ancient times in different sources, mainly in coal, oil and natural gas deposits. This acts as a big (very big) carbon sink. its also trapped in the bottom of the oceans and in the permafrost (alongside methane, but this will be discussed on a point later). When any hydrocarbon compound is subjected to a combustion reaction, it releases H2O and CO2 as waste product + heat and light (if the reaction is strong enough). This even happens on most of the chemical reactions that are necessary to life. This carbon (the one that was trapped on the fossi fuels) has been used extensively since the industrial revolution.
http://www.windows2universe.org/eart...co2_cycle.html
http://www.sartep.com/chem/tutorials...ete+Combustion
https://en.wikipedia.org/wiki/Combustion
https://www.mhi-global.com/discover/.../history.html4
Third evidence: since the industrial revolution the carbon present on the atmosphere has seen increasing numbers, even more in the recent years.for thousand of years, CO2 has been part of our air in a stable proportion. this hasn't been the case since the 1950s, when widespread use of internal combustion engines and plastic usage went global (plastic manufacture also releases CO2). Methane atmospheric levels are higher too, and methane is a waste product of cattle (it's litterally part of cowsh*t). It's needed to be said that we can accurately predict past levels of different gasses present in an ancient atmosphere, mainly because it gets trapped in bubbles on the antarctic ice.
https://en.wikipedia.org/wiki/Atmospheric_methane
http://climate.nasa.gov/climate_resources/24/
https://scholarsandrogues.com/2012/0...-year-old-air/
Fourth evidence: Natural causes cannot be accounted for this increase in CO2 and CH4 levels (such as a natural decrease in carbon sinks, or volcanism).
volcanic activity has remained mostly stable in the past 100s of years, so that emissions are also stable. And interestingly, most of the volcanic eruptions produce localized (and global when its a megavolcano) cooling, because of the sulfur compounds that are released that block sunlight (and heat, and add to that the acid rain). Even in a weird way, climate change affects the rate of volcanic eruptions. Solar activity cannot be accounted for the increase of temperature, for it has been stable/lower than before.
https://www.scientificamerican.com/a...noes-affect-w/
http://ete.cet.edu/gcc/?/globaltemp_carbon_cycle/
http://www.livescience.com/25936-cli...volcanism.html
https://www.skepticalscience.com/sol...g-advanced.htm
Fifth evidence: The global temperature has been higher in the recent years, increasing in a rate never seen before (some scientist say that its even on a rate comparable to a great dying extinction event). It's very important to note not only the absolute temperature, but the speed of said warming
http://www.npr.org/sections/13.7/201...climate-change
http://www.astrobio.net/climate/glob...e-great-dying/
https://en.wikipedia.org/wiki/Temper...ast_1000_years
http://earthobservatory.nasa.gov/Fea...ming/page3.php
Sixth evidence: Ocean acidification. This is part of the increase of CO2 in the atmosphere. As carbon dioxide is dilluted on seawater, it undergoes a chemical reaction that forms carbonic acid. This does, in fact decrease the Ph of the oceanic water (as Ph goes down, it gets more acidic). This makes shell formation (for molluscs) much more difficult, and can prove fatal for many species.
http://ocean.nationalgeographic.com/...acidification/
https://www.skepticalscience.com/oce...al-warming.htm
Seventh evidence: Floods/Hurricanes/Droughts much more prevalent on the recent years. The extreme temperatures makes this events much more typical than before, and in the case of hurricanes (typhoons) it's because of the higher energy that can be used (higher than before). Have to add that Hurricanes and theses type of storms works like an engine, using heat as energy
https://www.gfdl.noaa.gov/global-war...nd-hurricanes/
http://www.climatehotmap.org/global-...s/drought.html
http://www.ucsusa.org/global_warming...l#.WGxG-VXhDIU
https://www.youtube.com/watch?v=z-w81QtY0ek
Eighth evidence: Species are moving north (or south) because of the change in temperature/rain, moving higher in latitude to a climate that suits them better, if they cant do that, they die
http://ihrrblog.org/2011/08/24/clima...er-elevations/
http://science.sciencemag.org/content/348/6234/571.full
Ninth Evidence: Some groups (Exxon mobil) reportedly knew about AGW since the 70s. But they tried to use money to get scientists for hire (i dunno what's the exact word) to muddy the waters and produce denialism. this happened because a policy that tackled climate change went against their business interests (like the ban on leaded gasoline and the controversy that happened before that... there's a chapter on cosmos that is dedicated to it).
https://www.theguardian.com/environm...denier-funding
http://www.motherjones.com/environme...science-denial
TLDR: there're insane amounts of evidence that proves that AGW exists. it's condensed on the IPCC report, here:
https://www.ipcc.ch/
and for policy makers (a real tldr) http://www.ipcc.ch/pdf/assessment-re...r4-wg1-spm.pdf
PS: if someone comes with another one, feel free to PM me