1. Temperatures rising globally, out of normal rhythm with hundreds of centuries before the industrial revolution
In the last 650,000 years, there have been 7 cycles of climate change on this planet. This glacial advance and retreat is important evidence of climate change. Right at the marking of the industrial revolution, temperatures began skyrocketing. You may refer to the graph below, courtesy of NASA data. Just in case you question the graph, it does come from a reliable source. Although, with the current head of NASA, who knows what the next graph will tell us. I digress. These past cycles were brought on by small vibrations in the earth's orbit, followed by a change in solar energy the planet receives because of this. So, no, it's not deniable that temperatures are out of cycle since the environmental footprint of man has increased.
"The planet's average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere.5 Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010". (climate.NASA.com)
2. Carbon dioxide levels in the atmosphere as demonstrated by ice cores
Ancient evidence of carbon dioxide levels can be traced through ice cores. Now, what exactly are ice cores? Ice cores are pieces of ice scientists (more like cylinders) that are extracted from an ice sheet or high mountain glacier. The bubbles of carbon dioxide trapped inside of them indicate the corresponding levels of carbon dioxide found in the atmosphere at that time. What has been uncovered is that over time, these bubbles have increased in frequency and volume. This means the earth has taken on higher levels of CO2 as well since man's carbon footprint has increased. I really don't know what there is to explain further.
"Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that the Earth's climate responds to changes in greenhouse gas levels. Ancient evidence can also be found in tree rings, ocean sediments, coral reefs, and layers of sedimentary rocks. This ancient, or paleoclimate, evidence reveals that current warming is occurring roughly ten times faster than the average rate of ice-age-recovery warming".(Climate.nasa.com)
3. Extreme Events
Ever notice the odd change in seasons recently? There's more precipitation, more hurricanes, earthquakes, and volcanic eruptions. This is due to that CO2 and subsequent greenhouse effect spoken about above. It shouldn't be a shock that increased temperatures have led to an increase in wildfires and heat waves. What about the flooding, and the hurricanes? That's due to rising of sea levels from glacial melting. All of these reasons build off of each other and my hope is that you make connections between all of them. I could write a whole paragraph on that but I will spare you the time since you're probably done reading this anyway and uninterested.
I'm going to leave you off with a quote that, if anything, may help you realize why you hold the opinion you do.
"In the United States, for some, the term "climate change" has become so politicized that it is being erased from websites, funding proposals and official documents" .(Kelly Levin, World resource institute).
P.S., If you are a Bill Nye fan, check out his book on this topic called "Undeniable". I seriously will lend it to you.
