How are global temperatures measured? and is it reliable?
Depends on the how far you want to go back in time. Prior to 150 years ago, you require various proxies (eg: ice cores) to determine past temperatures, CO2 levels, etc. The past 150 years has been measured with land, sea and air based scientific instruments, while satellites are now used as well (past 40-50 years). The proxies and scientific instrument based data match up over the crossover period (late 1800s) [n.b. post-1960 the tree ring proxy deviates but that's known to scientists]. Measurements are more reliable with improving technology.
Have temps been taken from the same places year after year after year since they started keeping records?
Not an issue as a process known as homogenisation is used to average out micro-climate differences over large areas.
Why do greenhouse gases create hotter summers and colder winters?
Increasing greenhouses gases mean the Earth's climate system retains more energy (more energy = global warming). This in time will increase the intensity and frequency of climate extremes (both hot and cold, etc). A weather event that was say a once in a century event may now occur more often.
In an age of fake news coming from old media where agendas and headlines are more important than journalistic integrity, how can I trust that what's being reported is actual fact and not just rubbish opinion pieces using stats to suit their argument.
im naturally a very cynical person and not ashamed to admit that I can't help but feel strongly that this is all being pushed in the background by some that stand to make A LOT of money from it. I have tried to read up on it as much as I can but find it extremely difficult to find reliable black and white answers.
The vast majority of scientists are thankfully not politicians nor politically biased journos and media commentators. Using a proof by contradiction, if AGW was false then the scientist(s) that showed it would immediately become the preeminent climate scientists being chased by the most prestigious scientific institutions/universities and private companies. Despite this carrot, the vast majority of climate scientists agree about AGW based on their views of the empirical evidence that supports AGW. The study of CO2 in the Earth's atmosphere goes back to the late 19th century (1896) and knowledge of AGW as far back as the late 1950s. Scientific consensus was pretty much reached by the late 1970s. That's a long time to ago to be pushing a "scam".
