Wet ‘dry season’ rings the changes

Wednesday July 15, 2015 Written by Published in Weather
Rongo and Ministry of Marine Resources staff carrying out surveys in the waters around Aitutaki. Rongo and Ministry of Marine Resources staff carrying out surveys in the waters around Aitutaki.

While many are still sceptical of climate change, it is undeniable that something in the air, and in the ocean, is changing in the Cook Islands.

 

So far the ‘dry season’ has been more wet than dry, and cold enough to have many swapping the air conditioning for a hot water bottle and fuzzy socks.

Previous CI News articles have already foretold of climate change’s effect on health and the environment, but new research has sprouted concern over the future of transport in the Pacific.

Changes in the winds over the Pacific caused by climate change could increase flight times and fuel use, producing more carbon emissions, say US scientists.

In addition to this, Climate Change Cook Islands say a change in winds could mean a change in ocean currents, which is already affecting local fisheries.

US scientists looked at flights between Honolulu and Los Angeles, San Francisco and Seattle-Tacoma, and found changes in winds predicted to occur as a result of climate change would create extra CO2 emissions annually, and cost an extra $1.4m in fuel.

Applying that to the rest of the world would mean an increase in total human CO2 emissions of 0.03 per cent, they say.

Kristopher Karnauskas and colleagues analysed the difference in flight time for roughly 250,000 flights in the North Pacific, and compared them with observed daily winds at cruising altitude, to identify the influence of wind patterns.

They then calculated the response of these winds to greenhouse gas-induced climate forcing using 34 global climate models.

Karnauskas says when looking at the Cook Islands, similar changes in emissions and fuel costs depend on where else in the world Cook Islands’ passengers are flying to and from. “One thing I can say with high confidence is that, on an individual flight-by-flight basis, this will not make a huge difference,” he says.

Karnauskas says that flights will be a minute or two longer or shorter, but nothing dramatic for the passengers.

However, he adds that the main significance of the study is that when you consider there are more than 100,000 flights per day globally, a minute or so can add up.

Managing director of Air Rarotonga, Ewan Smith, says they spend about $2.5 million annually on jet fuel.

But, Smith says they have not experienced any effects of changing weather so far and that these scientists are only looking at the macro situation.

“The primary effect they are predicting is on the behaviour of jet streams that exist at very high altitude, above where we fly domestically,” he says.

Smith says the results of this study are not likely to have any relevance to domestic flights in the Cook Islands in the near or medium term.

Changes in flight times and emissions aside, staff at Climate Change Cook Islands say changing winds may already be affecting ocean currents.

Dr Teina Rongo says intensification of the trade winds has already been indicated in the literature.

“I am certain that this change will have an effect on travel, but I have neither information nor the expertise to talk about that,” he says.

However, Rongo says this change has an obvious influence to the marine environment, which he can talk about.

“For example, we have noticed through our interviews with elders and fishers that throughout the Cook Islands, ocean currents have become  stronger, and stronger ocean currents can equate to stronger winds.”

As a result, Rongo says fishers are finding it hard to bottom fish for deep sea species, especially tuna and manga.

“Although fishers are adapting to these changes by doing more surface fishing like trawling, this is costly as it requires more fuel,” Rongo says.

Change in currents may also explain the decline in fish recruitments in recent years throughout the Cook Islands, with strong currents taking fish larvae away from their natal reef, Rongo says.

In this regard, he says this change is very concerning for the Cook Islands because it will impact on food security, reef recovery and more.

This issue of stronger wind currents is only adding to growing concern over the current state of the world’s seas.

Another alarming new study from the University of California has found that nearly 66 per cent of the world’s seas, including the Pacific, show evidence of increasing human impact, driven mostly by climate change pressures.

The international team of researchers mapped out the changes in how much Earth’s oceans are being affected by human-related stressors such as fishing, pollution and sea level rise over five years.

Alongside their main finding, they saw that five per cent of the seas were so bad they would need immediate attention to recover.

Look out for another article in the Saturday edition of CI News to find out more about how climate in the Cook Islands has changed over the years. 

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