CO2 is the flavour of the month (err, last 20 years), but, in many ways, it’s hard to justify it as the dominate force driving our climate. We just don’t have substantial evidence supporting it. No, seriously, this is an oft-ignored point, I still await a single bit of evidence to convince me there is anything behind the CO2 argument. Science, at the periphery of knowledge, is mostly shades of grey, and thankfully so, or it would be rather dull. However, is there “Global Warming” (implicitly defined as CO2 driven), well give me one chart of reliable data, I’ll consider it willingly and put the grey back into a black-and-white issue. Until we have this, can we explain, at least qualitatively, the alternative, major drivers that are leading to the current global warming?
Fortunately, the answer is “yes” and these forces, unlike CO2, do have substantial amounts of evidence supporting them.
What are the possible forces? Well, plants absorb CO2, ice reflects sunlight, greenhouse gases absorb sunlight and clouds both absorb and reflect sunlight… These all influence the Greenhouse effect, which is an important temperature input. But, are they primary drivers of Earth’s climate? What really feeds the system its energy? Well, it’s generally accepted as the sun and the sea. In particular, we could be really looking at the cycles of Sunspots, which are flares of intense magnetic activity, and the ocean currents. It is likely that global temperature is controlled by solar energy and then modulated by that phenomenal sump of energy that is the world’s oceans. The solar and oceanic cycles sometimes offset and sometimes complement each other. The many other influences, such as man-made CO2, are relatively minor and often offset each other.
The significance of sunspots and ocean currents in driving global temperatures has long been recognised and has stood the test of time. As far back as 1801, William Herschel noted an apparent connection between wheat prices and sunspot records. The evidence for both sunspots and ocean currents being the primary drivers of climate change is considerable, so why have we suddenly put the finger of “blame” on CO2? In addition, the current, gentle, warming they drive is far from catastrophic, it is beneficial.
The following video clip from the movie, “Church of Global Warming” shows the “sun and sea” hypothesis in action:
THE SUN (sunspots)
The sun’s Total Solar Irradiance (i.e. total energy output) does not vary, we believe, too significantly. Thus, how does the sun so noticeably influence Earth’s temperature? Well, if you concentrate instead on the intermittent spikes in intense magnetic activity, i.e. sunspots (or flares), then you have something to work with. Sunspot activity is highly variable and could reasonably account for the drastic modulations in Earth’s weather.
Global Warming has been happening for 400 years (not just during the last century of industrialisation as the IPCC quite controversially suggest with their famous Hockey Stick evidence – video here). In addition, it correlates well with sunspot levels, as seen by direct, observational data by astronomers. Since the Maunder Minimum (virtually no sunspots) of the 1600s, both sunspot number and global temperature have risen with a strong, significant correlation:
A sunspot in action – it’s affect on the Earth’s magnetic field (the Aurora Borealis is a frequently seen demonstration of its effects on our atmosphere’s chemistry):
THE SEA (ocean currents)
What are the “Pacific Decadal Oscillation” (PDO) and “El Niño / La Niña“? And why are they important in climate change?
“El Nino / La Nina”, which are two sides of the same coin, and the “Pacific Decadal Oscillation” (PDO) are both ocean currents. They are both in the Pacific, the former being equatorial, the latter in the north. Both oscillate between warming and cooling phases of sea surface temperature (SST), which are above or below long-term averages. For “El Nino / La Nina”, El Nino is the negative, warming phase, La Nina is the positive, cooling phase. Conversely, for the PDO, a warming phase is called “positive” and the cooling as “negative”.
In particular, El Nino refers to the extensive warming of the central and eastern Pacific that leads to a major shift in weather patterns across the Pacific. This includes increased convection or cloudiness in the central tropical Pacific Ocean and weaker easterly, trade winds. In eastern Australia, however, these events are associated with an increased probability of drier conditions.
Adapted from: BOMDuring, a neutral or La Nina event surface temperatures are cool in the east Pacific Ocean. Thus, Air travels to the low pressure in the west tropics (this process is known as the “trade winds”). En route, the air warms and moistens, which leads to clouds in Australia that increase local rainfall, but noticeably decreases daytime temperatures.
Adapted from: BOMDuring, an El Nino event surface temperatures are warm in the east Pacific Ocean. This halts the easterly trade winds. Pressure thus increases over Australia and less oceanic moisture is delivered there. This reduces cloud cover and thus rainfall, but can increase daytime temperatures.
For more on El Nino / La Nina check here.
This is Roy Spencer’s (recognised, satellite data, analysis guru) take on the PDO and El Nino:
“The Pacific Decadal Oscillation (PDO) is an internal switch between two slightly different circulation patterns that occurs every 30 years or so in the North Pacific Ocean. It was originally described in 1997 in the context of salmon production. It has a positive (warm) phase that tends to warm the land masses of the Northern Hemisphere, as well as a negative (cool) phase.
Like the El Nino and La Nina oscillation of the tropical Pacific (also called the El Nino – Southern Oscillation, or ENSO), the PDO represents two different average circulation states that the ocean-atmosphere system seems to have a difficult time choosing between. But whereas ENSO changes every few years, the PDO changes every thirty years or so. This long time scale makes the PDO a potential key player in climate change.”
Why does the ocean surface temperature matter?
Ocean surface temperatures influence the air temperature above them and evaporation rates. High temperatures lead to increased cloud cover, which can lead to warming or, bizarrely, cooling depending on the type of clouds formed and their altitude. Even the IPCC, who like to blame it all on CO2, acknowledge this:
“…cloud feedbacks remain the largest source of uncertainty…” (IPCC Report 2007)
“Ocean Conyevour Belt”
This is a note of clarification. A lot is made of the PDO in the climate change debate and perhaps rightly so, however, this may be a debate bias because most of the oceanographic research comes out of the U.S. The PDO is a significant part of the “Ocean Conyevour Belt” (the global, continuous, ocean current circuit), but we should remember that it is still only one part of it:
The main drivers of global temperature are probably the sunspot levels and the ocean current temperatures. There are other short-term, temperature drivers (such as CO2), but Global Warming alarmists chose to gloss over the well-known, long standing evidence. The weight of this evidence indicates that it is the combination of the “sun and sea” that most likely drives global temperature.