The following graph was published and the source is wattsupwiththat.com
It is a snapshot from June 2005 to May 2022, taken from data available at the US Climate Reference Network: ref: https://www.ncei.noaa.gov/access/crn/qcdatasets.html
Using the same data I have constructed the same graph – verified.
At first, glance that looks like a 15-year pause.
Research Question: Is it reasonable to conclude that there has been no increase in temperature in the USA since 2005, and what if anything can be said about the worldwide situation?
Based on the trend shown in the graph from 2005 it looks like there is an upward trend – see the higher highs, see the bunching effect near 2015-2022, but maybe I see incorrectly – biased.
Time series are hard to study. There are often trends that are hard to see.
One thing to do is consider a moving average and look at the yearly trend.
If we do this a trend is easier to spot. The lower average temperatures are increasing and the time period is shorter.
The top is fluctuating, much like the first graph. But you will notice that the trend line shows a positive gradient (i.e. the number in front of x)
The UAH is satellite reconstruction by Dr Spence and RSS is via a private firm. You notice the key thing is that they agree.
This is not a trick it is a simple well-used method to detect trends.
It is very clear there is an upward trend.
The full set of data from 1900 shows the entire trend.
This graph captures nicely the way the average has moved upward over time.
Initially, it was low, then there was a jump and then a fall and plateau and then a gradual rise.
Let’s look at some other indicators
These can be found at https://www.epa.gov/climate-indicators
- High and Low temperature pattern
What you will notice is these are both increasing and Min more it is more than Max. This is exactly what has been stated by climate science.
- Heat Extremes
The trend is clear, extremes of heat is increasing.
- Seasonal patterns
As I said earlier a time series is hard to study. A time series of data is made up of the raw data + trends + seasons + errors.
What is shown above is the seasonal data. Winter shows a clear trend.
I have recently completed a study of the time series data for the Arctic Sea Ice Extent ie how much ice there is at any point in time. The data is derived from Satellite readings since 1978. The basic finding is that the amount of the max sea ice has fallen from 16mk^2 to 14mk^2. It will get published in due course.
Back to the original research question. I think it is clear the original graph on its own does not present sufficient evidence that (a) warming is not or has not occurred in the US and (b) it says nothing about the world.
There is also much discussion on blogs about Urban Heat Island (and airports). The data that you see is adjusted to these effects. Raw data suggests a significant bias, which is why it is removed. Much of what humans do is set around bias either personal or hidden in the data. For this reason, researchers spend a lot of time detecting and removing it.