The gold-standard for climate science temperature measurements is produced by the advanced, 24/7 monitoring accomplished by orbiting satellites.
Unlike the deployed small number of geographically-sparse surface thermometers, satellites essentially cover the entire world on a continuous basis.
And unlike earthly thermometers, which more often than not reside within known hot-spots, such as metro airports and urban heat sinks of concrete, asphalt and steel, satellite measurements are not affected by human structures, not by transit activities, not by industrial production, and not by power generation.
Satellites are the only available technology scientists have that truly measure temperatures in a global fashion, without all the inherent biases influencing surface-based thermometers.
This unrivaled, sophisticated technology has been performing its empirical measurement duties over the last 38 full years, which the adjacent chart is a plot of. Each month's temperature average is shown by an orange circle (each circle is the average of the two major lower troposphere (LT) temperature satellite datasets - RSS and UAH). The red curve is a moving 12-month simple average of the monthly datapoints.
In addition, the chart includes a plot of NOAA's monthly atmospheric CO2 level (see black dots) and its moving 12-month simple average (grey curve with arrowhead).
#1. As measured, the monthly CO2 levels continue to steadily increase at a linear rate, which if maintained, will almost reach an atmospheric level of 555ppm by 2100AD.
#2. As measured, the temperature trend for the last 38 years (starting with January 1979) indicates an increase of 1.07°C by 2100AD, if that trend is maintained.
#3. As measured, the global average temperatures sporadically gyrate up/down, which the red curve clearly depicts.
#4. As measured, there are very obvious significant warming/cooling spikes that took place in the recent past.
#5. As measured, global LT temperatures spiked warmer during the 2015-2016 period, achieving the highest recorded temperature during February 2016, exceeding the previous high from April 1998 by some +0.12°C. March 2016 was the only other month exceeding the April 1998 measurement (approximately by+0.005°C).
#6. As measured, global temperatures typically spike down after a strong spike up.
#7. As measured, LT global temperatures have declined considerably from the February 2016 high to the year's low of December 2016 - an average global temperature that is below both the December 1987 and December 1998 global temperatures (see magenta-tinted circles), respectively 29 and 18 years ago.
#8. As measured, this gold-standard empirical evidence reveals that only 12% of global LT temperature datapoints since December 1987 were higher.
#9. As measured, the combined RSS and UAH dataset averages show an extended pause in the overall warming - i.e. the hiatus - that stretched across a span from about 1999 to the beginning of 2015.
The below points should be viewed as opinions, or if one wants to be fancy about it, conclusions and assessments. While they are opinions, the actual empirical evidence from the satellites - the climate science gold-standard - is quite supportive.
- Global LT temperatures will continue to decline sporadically throughout 2017, which the satellite empirical evidence from the past 38 years (456 monthly measurements) suggests will be a normal/natural cooling reaction to the warming spike.
- During the next 18 months, it can be expected that a low temperature point will be reached before a rebounding commences.
- Despite the steady increase of CO2 emissions and levels, the natural oscillation phases known as El Niño and La Niña totally overwhelm any modest warming influence of this trace greenhouse gas.
- Global LT temperature spikes, both up and down, are primarily due to major natural climate oscillations/cycles, plus natural phenomenons, such as volcano eruptions; temp spikes are not a result of steadily rising human CO2 emissions and/or atmospheric CO2 levels. The 2015-16 El Niño produced the highest temperature anomaly spike since satellite measurements began.
- Significant global absolute LT temperature warming, as of December 2016, has not taken place since December 1987. There indeed have been multiple 'hot' and 'cold' years in between these two Decembers but the latest December absolute temperature is still lower than that of December 1987.
- Global LT temperatures are highly unlikely to achieve a 3 to 6 degree increase by 2100AD that many consensus experts speculate will happen.
- The identified modest warning trend from modern satellite measurements supports the historical evidence and anecdotal recordings that a modest warming has taken place since the end of the Little Ice Age.
- The orthodox anthropogenic hypothesis of catastrophic global warming that much of high-level governmental policy-making is based on, is for all practical purposes, invalidated.
Regarding that last point, consensus climate science has proposed a hypothesis on the claim that climate physics dictates that rising atmospheric CO2 levels will warm the atmosphere substantially, thus causing a positive feedback loop, which will then continuously accelerate warming until a tipping point of runaway temperatures take place, turning Earth into the next Venus. This one simple sentence is a nutshell summation of the supposed complex climate physics of "dangerous" global warming that has actually been tested.
The result of that 38-year long real test is that the gold-standard satellite empirical evidence clearly invalidates this hypothesis of positive feedback(s) leading to runaway, catastrophic warming.
Fortunately for the world and its populace, the climate science dogmatic consensus is robustly without any scientific empirical merit. It may indeed get warmer but the catastrophic predictions are not connected to science reality.
Note: Excel used to calculate averages, trends, and to chart the dataset plots.