CO2 is heavier than air. Most of the human-generated CO2 ends up in the ocean [0]. This changes the pH of the ocean water, making it slightly more acidic. pH changes and nutrient changes (CO2 + agriculture runoff) probably explain the observations of changes in the types of plankton better than temperature changes.
The climate is a complex system with lots of inputs. It is fundamentally dishonest for the climate crusaders to whip up a frenzy (hockey-stick doom prophecies) on incomplete models and data.
Changes is solar activity (sun spot cycles) and underwater volcanic activity aren't really incorporated into the climate scientists' models, because they don't have much/any data. Temperature sensors have only recently been placed on the Juan de Fuca Ridge [1] (just off the coast of Oregon/Washington/British Columbia). The volcanic trenches in the deep ocean have no network of temperature sensors, or long-term activity data.
The Wall Street-owned utility model for the provision of electricity is technically and ideologically bankrupt, but the "green energy" replacements aren't much better. Solar panels wear out after a few decades, and are not easily recycled with current technology. Most people can't put a wind farm on top of their house, so wind-derived electricity is still purchased from a utility company.
I wrote a piece titled use as much energy as possible: "Under our current system of money and finance, Wall Street is trusted to plan for the economy's future energy needs. Wall Street invests where it sees the most potential for payoff, and THEY make more money when the economy uses as much energy as possible.
"Like a rigged carnival game, the energy economy is specifically distorted so that we have little choice but to send lots of money to our financiers' energy companies. [...]" [2]
[0] "The constant atmospheric CO 2 concentrations in the centuries prior to the Industrial Revolution suggest that the oceans released a small amount of CO 2 to the atmosphere to balance the carbon input from rivers. Today, this trend is reversed and the oceans must remove CO 2 added to the atmosphere from human activities, known as anthropogenic (humanderived) CO 2. In the 1980s, the oceans removed an estimated 2.0±0.6 Pg of anthropogenic CO 2 each year. Because humans are producing CO 2 at an everincreasing rate, the average ocean removal rate increased to 2.4±0.5 Pg of carbon each year in the 1990s." - http://www.waterencyclopedia.com/Bi-Ca/Carbon-Dioxide-in-the...
[1] https://en.wikipedia.org/wiki/Juan_de_Fuca_Ridge
[2] https://teslabox.com/use-as-much-energy-as-possible/ [I wrote this in 2011 - all my picture links are broken, hmm...]