Hourly temperature data do not support the views of the Climate Deniers:
Evidence from Barrow Alaska
Abstract
Survey evidence has indicated that a significant percentage of the
population does not fully embrace the scientific consensus regarding
climate change. This paper assesses whether the hourly temperature data
support this denial. The analysis examines the relationship between
hourly CO2 concentration levels and temperature using hourly data from
the NOAA-operated Barrow observatory in Alaska. At this observatory, the
average annual temperature over the 2015-2020 period was about 3.37 oC
higher than in 1985–1990. A time-series model to explain hourly
temperature is formulated using the following explanatory variables: the
hourly level of total downward solar irradiance, the CO2 value lagged by
one hour, proxies for the diurnal variation in temperature, proxies for
the seasonal temperature variation, and proxies for possible
non-anthropomorphic drivers of temperature. The purpose of the
time-series approach is to capture the data’s heteroskedastic and
autoregressive nature, which would otherwise “mask” CO2’s “signal”
in the data. The model is estimated using hourly data from 1985 through
2015. The results are consistent with the hypothesis that increases in
CO2 concentration levels have nontrivial consequences for hourly
temperature. The estimated annual contributions of factors exclusive of
CO2 and downward total solar irradiance are very small. The model was
evaluated using out-of-sample hourly data from 1 Jan 2016 through 31 Aug
2017. The model’s out-of-sample hourly temperature predictions are
highly accurate, but this accuracy is significantly degraded if the
estimated CO2 effects are ignored. In short, the results are consistent
with the scientific consensus on climate change.