No Hockey Sticks: Studies Reveal Long-Term Lack of Warming

Guest Blogger / 1 min ago

A new temperature reconstruction, using proxy temperature
measurements from locations in central Asia, has revealed that there has
been no warming in the past 432 years.

by Vijay Jayaraj

The Global Warming “Hiatus” or Pause

The word “hiatus” became popular in recent years after the discovery of a pause or hiatus in global warming. There has been a lack of warming in the atmosphere since 1999, despite the predictions of computer climate models.

The theories that support a hiatus in global warming vary in their
conclusions regarding the overall climate scenario. While some forecast
that the hiatus will be brief, others say it represents a major shift in
our climate system.

Regardless of whether there has been significant shift in the global
climate trend, the word “hiatus” implies that there has indeed been a
warming trend and that it has stopped—at least momentarily.

That is partly correct, as many well-established scientific studies
indicate gradual warming since the end of the Little Ice Age in the 17^th century.

It can, however, be declared with absolute certainty that there has been no dangerous
warming in the past two decades, and even in the past 200 years. The
post-Little Ice Age warming trend has been anything but dangerous,
causing hardly any negative impact on the ecosystem or the life forms.
Instead, it has brought lengthened growing seasons, more abundant
vegetative growth, and more abundant food for people and everything
else.

It Is More than Just a Hiatus: Long-term Stability, Followed by Cooling

But more and more studies are beginning to indicate that there has
been no significant warming trend in the past five centuries.

Among them is the recent paper by Byambaa et.al., which reveals a lack of warming in Central Asia since 1580 A.D.

The paper used tree ring-width proxy temperature measurements to
calculate the mean June‐July air temperatures for the period 1402–2012
and June–December precipitation for the period 1569–2012.

**Figure 6**:
A graphical comparison of tree ring based temperature reconstructions
from the southern Altai. June temperatures for the eastern Kazakhstan
Altai since 1698 (a), mean May–September temperatures for the western
Chinese Altai since 1639 (b), June temperatures for the middle Chinese
Altai since 1570 (c), mean June–July temperatures for the eastern
Chinese Altai since 1613 (d), mean June–July temperatures for the
southern Mongolian Altai since 1402 (e, this study). Thin grey lines and
thick black lines show the reconstructed temperature and 13‐year
low‐pass‐filtered curve, respectively. (a–d) from Zhang *et al.* (2015).
Dark and light grey bars show cold and warm periods. The cold periods
of low solar activities are named by S, Spörer; M, Maunder, D, Dalton,
and G, Gleissberg minima (Schwikowski *et al.*, 2009) and triangles indicate volcanic eruptions (Briffa *et al.*, 1998; Eichler *et al.*, 2009)

The authors conclude that the past 5 centuries have been relatively cooler. They also find the 20^th century to be slightly warmer, but the warming was discontinuous. However, the 20^th
century warming eventually collapsed due to late 20th century cooling,
which they deem common across the mountains of China and Nepal. They
also find that solar cycles and volcanic activity were the major reasons
for temperature anomalies during the past 5 centuries—not carbon
dioxide.

Numerous other studies have attested this recent cooling in Central
Asia, especially China. Temperature readings from 118 national weather
stations since 1951 in Northeast China reveal a remarkable and significant cooling in China since 1998, the same year since which global atmospheric temperature failed to show any significant warming. Other studies show this trend over all of China.

China is not the only country to experience this late 20^th century cooling.

A dozen peer-reviewed scientific papers published during the past three years reveal that the Arctic ceased to warm and the Antarctic began to cool. Other papers report that the 20^th century also saw a significant dip in global ocean temperatures.

For example, surface temperatures from Japan have shown no warming trend during the past 50 years and are now beginning to show a cooling trend. And scientists have warned that there might even be a 1-degree Celsius global cooling by the year 2100.

The emergence of these studies has particularly made climate
scientists suspect that our climate system’s biggest influencer could be
the sun, not greenhouse gases like carbon dioxide.

Hundreds of scientific papers support their intuition and document the natural variations in the climate system owing to the impact of the sun.

The recent cooling, as revealed in the studies mentioned earlier, coincides with the weakest solar cycle on record. The current solar cycle (number 24) is the weakest on record, and scientists have predicted that the next two solar cycles will be much weaker, resulting in more cooling.

In all likelihood, we will experience significant cooling in the coming decade, not a mere hiatus in warming.

Our understanding of the earth’s climate system is still in its
infancy. With more and more empirical evidence, it will take us at least
a couple of decades to develop a better grasp of how our climate system
works.

Vijay Jayaraj (M.Sc., Environmental Science, University of East
Anglia, England), Research Associate for Developing Countries for the Cornwall Alliance for the Stewardship of Creation, lives in Bangalore, India.