= Firstly it is perfectly true that about 98% of scientists agree that world climate is changing, and indeed most also maintain world climate has always been changing throughout the history of this planet. But what increasing numbers are sceptical about and some use the word "scam" about is whether the theories of the UN International Panel on Climate Change (UNIPCC) contending unless mankind cuts back drastically on CO2 emissions then all life on earth is doomed is really true. That is the issue we need to review here with an open mind.
In fact today some of those who used to argue very passionately that global warming was the major threat facing mankind have now replaced the words "global warming" with the words "climate change" specifically it seems because there has been a verifiable levelling out in the rising in global temperatures, and also some scientists today are maintaining (rightly or wrongly) that the trend is now towards global cooling rather than global warming.
See https://wattsupwiththat.com/2018/03/18/approaching-grand-solar-minimum-could-cause-global-cooling
But nobody really knows for sure. Everything is just speculation and theorising using apparently flawed computer models to try to predict trends. I used to believe global warming was a serious issue that needed to be addressed just like some of those answering this question do. But although I am still not certain, I am finding myself increasingly drawn to the view that it could indeed well be a scam, but I am keeping an open mind on the question as everybody should.
I am afraid however it is simply not true that "the science is settled" as stated by certain politicians like President Obama and Al, Gore. One thing that is emphatically apparent is that the science is definitely not settled as there is increasing skepticism among a considerable section of the most eminent scientists all over the world regarding the original theories put forward by Al Gore in his movie "an inconvenient truth" in collaboration with the UN International Panel on Climate Change (UNIPCC). Since that movie was made and widely believed by huge numbers of scared people some things claimed to be happening by Al Gore have been found to be incorrect.
Increasing numbers of expert scientists are among those who have changed their mind from supporting Al Gore's and the UNIPCC theories to being highly sceptical of them. These include Dr Mike Hulme, a prominent climate scientist and UN-IPCC insider. Dr Benjamin Santer, author of the 2007 IPCC report chapter on the detection of greenhouse warming - Dr Richard Lindzen (Atmospheric Scientist) Former Professor at Massasuchetts Institute of Technology UNIPCC and lead Author, Dr John Christy - Professor and Director of the Earth System Science Centre at the University of Alabama, Doctor Yury Izrael, past UN IPCC Vice President and Director of Global Climate and Ecology Institute, member, and others of the highest eminence whose names were attributed to supporting papers claimed to support the UNIPCC theories have demanded their names be removed from that as they simply can not support the UNIPCC's latest reports any more.
Nor is this view apparently a minority opinion among the world's learned scientists a study organised by Oregon Institute of Science and Medicine signed by about 9,000 Scientists who have PhDs and about 31,000 scientists altogether contends "There is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gasses is causing or will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere and disruption of the Earth's climate. Moreover, there is substantial scientific evidence that increases in atmospheric carbon dioxide produce many beneficial effects upon the natural plant and animal environments of the Earth." .
Supporters of the UNIPCC theories in recent year have been increasingly basing their contention that global warming is real on statistics from NASA which appear to show two of the warmest years ever recorded have been in this century. But an investigation by probably the world's top weather forecasting expert John Coleman (founder of the Weather Channel) provides very strong evidence challenging that in a TV documentary on KUSI TV in which what he exposes what he calls "systematic and purposeful deceit in statistical evidence of alleged global warming" to have been perpetrated by NASA's Goddard Institute for Space Sciences and NOAA's National Climate Data Center following similar falsification and intent to deceive world opinion being exposed by hackers into the Climatic Research Unit of the University of East Anglia. If you want to watch this to analyse the evidence please Google "John Coleman global warming hoax KUSI" as his exposures can be watched in full on YouTube to further answer the question expertly in very great detail.
One other very important piece of evidence suggesting the UNIPCC are wrong in their belief that the 20th century and 21st century are warmer than ever known before in world history concerns the "Medieval Warm period" (1000-1200 AD) when Planet Earth was in fact provably much warmer than now. Although supporters of the UNIPCC have tried to deny that it was warmer than now, very many hundreds of scientists have written peer reviewed papers proving it was in fact much warmer than today in northern latitudes with irrefutable evidence of the Vikings farming in a green Greenland in that epoch (a part of the world that is today covered in very thick ice)! Since then there have of course been various ice ages as well as inter glacial periods before humanity first arrived on Earth. It is hardly necessary for me to point out that the referred to medieval warming period was well before the industrial revolution in world history so it can not possibly be attributed to CO2 emissions nor human activity. Also there is very strong evidence that the dinosaurs became extinct as a result of huge changes in world climate 64 million years ago, and very many years before man ever existed.
I think you have asked a very good question and this is an issue everybody should keep an open mind about. Nobody really knows the truth, and there are widely different beliefs, prejudices and vested interests involved in both science and political circles. But true science should always be about questioning the evidence and being sceptical not accepting things blindly deemed politically correct by politicians with little or no scientific background.
BTW its getting colder not warmer in the Antarctica.
Newly analyzed Nasa satellite data from east Antarctica shows Earth has set a new record for coldest temperature ever recorded: -94.7C (-135.8F). It happened in August 2010 when it hit -94.7C (-135.8F). Then on 31 July of last year, it came close again: -92.9C (-135.3F). Is that proof of global cooling? The discrepancy between the global temperature and the land-based readings is down to the changes in measuring techniques that have biased oceanic readings much higher.
The engine air-intake temperature sensor readings on ships are now incorporated into the global readings - a desperate move, as these are inaccurate sensors only intended to supply the engine's fuelling management with intake density readings.
No honest 'scientist' would accept such rubbish data from cheap, uncalibrated, sensors which are either reading the temperature inside a hot engine room - or air that has just drifted down the length of a baking steel deck.The inclusion of such unreliable data can only be for one purpose - to skew the overall temp reading higher, as such sensors can only report above-ambient temperatures - never below.