Fert Options with Robin Boom Agronomic Advisory Services

Almost daily we read or hear in the media items about climate change and the impending danger the planet is in. School children around the country held protests in May. In June, Wellington City Council stated climate change would be front and centre of any future policy-making. With almost half of New Zealand’s greenhouse gases coming from agriculture, there is pressure for a reduction of sheep and cattle farming and for more land to be planted in trees. However, is climate change something we humans can control? Or is it largely driven by natural forces we cannot control?

Ice melts

Real science progresses through falsification as advocated by Karl Popper, demarking scientific from unscientific theories. I believe Anthropogenic Global Warming is a theory that can easily be falsified. The reality is that our climate has been radically changing on this planet for millions of years. During the last two millions years there have been a series of ice ages and warming periods, driven by the Earth’s axial tilt and orbit around the sun. Around 12,000 years ago, at the end of the Last Ice Age, northern Britain was covered in glaciers and our own Southern Alps were covered by a massive ice sheet. This Ice Age, which peaked around 22,000 years ago, is called the Late Glacial Maximum. And from about 19,000 years ago until 6000 years ago, as these ice sheets melted, the sea levels rose 120 metres, about one metre per century – double what it is expected to in this current century. So cries of sea levels rising alarmingly fast are misleading and are in line with what took place naturally for more than 12,000 years, with no human influence whatsoever. As ice melts, sea levels rise.

Interglacial period

Two thousand years ago, it was warm enough in Britain for the Romans to grow grapes, something which could not happen for the 1500 years of the Little Ice Age, which ended about 1850. This is why climate alarmists use the date 1850 as their benchmark, claiming global temperatures have risen by 0.8 degrees Celsius since then. They avoid saying that the world got colder for 1500 years after the time of Julius Caesar, and even today it is still not as warm as it was 2000 years ago. It also needs to be borne in mind that most of the time biological life has been on this planet, there have not been polar ice caps, and that we are currently in an interglacial period. Antarctica has its own oil and coal reserves from plant life that once existed on this now barren, frozen, uninhabitable continent.

Long-term view

Although the claimed ‘hockey stick’ effect of increases in atmospheric CO2 levels from 250ppm to 380ppm in the last 200 years from the burning of fossil fuels is probably making some contribution to seasonal fluctuations, its overall impact is likely to be exaggerated. Taking a long term view of our planet, when CO2 levels were five times higher than they are today, in the Jurassic period, speciation occurred on a massive scale. In all likelihood, with the high greenhouse gas effect, plants were growing very quickly and large because of all of the available plant food in the form of carbon dioxide, which explains why the massive herbivorous dinosaurs got to grow so large. A lot of this excess CO2 has since been incorporated into coal and oil reserves, which we have been mining for the last 200-300 years, and are now putting back into the atmosphere. But it is highly unlikely we will ever see CO2 levels get anywhere near the levels they were at 250 million years ago.

Greatest asset

The atmosphere currently contains only 0.001 per cent of all carbon at the surface of the earth, most of which is contained in sedimentary rocks like limestone, and even the oceans contain almost 50 times more CO2 than the atmosphere. Beneath the Earth’s crust there is untold carbon resources, which get belched out via volcanoes, thermal vents, tectonic plate shifts etc. All of these factors as well as the tilt of the Earth and proximity to the sun have a much greater influence on our changing climate than any human-induced greenhouse effect. So in real terms, thinking we can change the climate may be akin to the legendary King Canute’s attempt at stopping the tide from coming in.

Our land, our whenua, is our greatest asset. It will feed and nurture us as a nation if we treat it right. Planting it in exotic, fast-growing conifer monocultures, which reach their maximum carbon absorption after only 30 years, is not the answer.

Robin Boom, CPAg, member of the Institute of Professional Soil Scientists. Ph: 0274448764. Email: agronomics@xtra.co.nz