The devastating floods which occurred during the past five weeks throughout north-east, central and south Trinidad have left many questioning the frequency and intensity of rainfall patterns—leading persons to wonder if it could be linked to climate change and what it would mean for T&T moving forward.
Questioned as to local rainfall patterns/trends observed in the last ten years, climatologist Kenneth Kerr, meteorological services, Piarco said, “Based on rainfall at Piarco, we found that for 2007 to 2017, annual rainfall totals were less than the 1981- 2010 average, for eight of those last 11 years.”
He added, “We have also analysed maximum consecutive five-day rainfall and maximum consecutive three-day rainfall for T&T from 1981- 2015, and it appears that these have been increasing in some areas and decreasing in others.”
Dismissing these trends as not significant, Kerr admitted, “Even though these are not significant, it is reasonable to state that global warming and associated climate change have been playing their role in the changes observed in local rainfall and extreme events.”
He explained increases in three- and five-day maximum rainfall totals corresponded with the type of changes expected regarding how the atmosphere is likely to respond to increases in the average local and global temperatures.
Asked whether climate change was a real or perceived threat, Kerr stressed it was essential to understand the rainfall pattern and difference in trends, if any, in T&T to ensure that the correct message is conveyed.
That message being, “Rainfall is a very complex feature of the local climate that is influenced by a multiplicity of factors that can cause several outcomes."
Kerr said rainfall in T&T is highly variable, both in time and spatially, in that each year and each season, records show rainfall totals have shown significant variations.
He said, “Rainfall also varies within each island and across each island, with some areas receiving twice as much rainfall as other areas, in the same month.”
Kerr claimed this strong annual variability was related to a variety of climate influencers, some of which were local while others were remote to T&T.
The remote influencers include both the El Niño and La Niña phases of the El Niño–Southern Oscillation (ENSO).
The effects of ENSO on T&T’s rainfall are what Met Office officials consider as natural variability.
Kerr said the effect of this phenomenon on local rainfall was well known and is considered to be the primary influencer of local rainfall changes, where the La Niña phase is associated with increased local rainfall and El Niño with decreased rainfall.
Claiming there was a strong relationship between local rainfall variability and the Inter-Tropical Convergence Zone (ITCZ) —the main weather feature for prolonged rainfall in T&T—Kerr added that the strength of the ITCZ is also influenced by ENSO, which makes for a very complex set of factors driving the local rainfall changes.
Based on this, he said, “We have always had natural climate variability in T&T and will continue to do so.”
“We have always had extreme rainfall weather events as well. What climate change is doing is shifting the range and the pattern of this variability.”
Referring to the two major flooding events in October 2017 and the recent October 2018 floods, both of which were disastrous in their way, Kerr said new questions have arisen, “Is this the beginning of a change in the pattern of late-season rainfall? Can we say that there is a shift from having just November as a very wet and flood-prone month that we are accustomed to?”
He said while extensive research had to be done to provide an appropriate answer, “It may very well be that we are seeing instead of November being the main flood month at the end of the season, we are now getting October as another flood month.”
To answer the question of whether climate change is real or not, Kerr said there is no disputing the facts as all the evidence show that we live in a warmer world today than ten years, 50 years, and even 100 years ago and this has led to the climate changing in the form of more extreme weather and climate events.
He added, “The culprit responsible for this warming is carbon dioxide and other greenhouse gases that are forcing changing in the temperature range that we normally experience; and this is causing the atmosphere to rain less frequently in our region while having a new capacity to rain more intensely when it does.
“Because of this, climate will continue to change, so we must find ways to adjust to the existing changes and the changes to come, and at the same time we must also implement new technologies and find innovative ways, such as using alternative renewable energy in order to reduce the rate of emission of great house gases, significantly.”
Kerr said, “The extreme and record-breaking rainfall that led to the disastrous flood in mid-October allowed the citizens to see exactly the kind of climate risks that the country now faces and will face in the future.
“It is safe to say that these types of events are the new normal but unfortunately, this is a normal that will continue to change for the worst because the expectations based on our physical understanding of the atmosphere, is that these extremes are on a path to becoming more extreme, lasting longer and occurring more frequently.”
As a result, the climatologist advised, “Therefore, it cannot be business as usual. We must change our behaviours from the individual to the national level if we are to be in a position to better cope and adapt to these new types of events.
“This requires action now, so that when faced with this type of extreme climate events - and we are going to face them more often now - we must be in a better position to respond and rebound in the shortest possible time to a state of normalcy.”
Kerr said climate change is real and has been real for a while.
However, “It may just be that as a country, we have not been paying enough attention to this issue in practical terms.”
He claimed, “Climate change has been appearing in many forms here in T&T. We have been having more extreme events such as higher local temperatures and greater heat leading to hot spells and the issuance of hot spell alerts.”
“We have seen the extreme local rainfall events leading to devastating flooding; we have experienced rainfall deficits that have led to increased dry spells and droughts with knock-on effects of increased bushfires and water scarcity. All of these threaten our coastal and farming communities, our cities, infrastructure, human health, biodiversity, tourism sector services and our on and off-shore resource-based economy, and the country’s overall sustainable development, in one form or the other.”
Recent flood no fluke
Declaring “The recent flood event was no fluke,” Kerr said the evidence was there for an event of this magnitude to occur.
He pointed out that in August 2012, there was the Diego Martin event; in November 2014, there was the Sangre Grande, Manzanilla, Mayaro event; in November 2016, there was the Matelot event; and last year, there was the October Divali event.
He said, “The question is were we paying attention?”
Acknowledging the devastating impact the October and November floods would have had on citizens, Kerr said well-planned adaptation could substantially reduce risks and avoid losses, as well as create or maximise opportunities due to climate extremes.
As a country, he suggested becoming more informed about how our climate is changing and what it means for us; becoming more organised in our approach to climate change adaptation; and becoming more proactive by taking continuous action to manage the environmental, economic and social risks associated with expected extreme events.
Kerr warned, “We have to recognise that T&T will not successfully adapt through central and local government alone.”
“Yes, it is central and local government responsibility for managing risks to public goods and assets including the environment, delivering government services, and creating the institutional, market and regulatory frameworks that can promote resilience and adaptation.
“But each person also has responsibility for understanding how climate change will impact them, their children, their jobs, their responsibilities, activities and business continuity.”
Calling for industry standards to be revised as it relates to infrastructure to ensure that and the new climate are in sync with good global practices, Kerr said, “Given the long lifetime of infrastructure, it is important that climate change adaptation be factored into infrastructure decisions now.”
“Citizens need to start thinking about climate change impacts and their consequences on their residence, assets, lives and livelihood.”
He urged, “Now is the time to think about retrofitting one’s residence.”
“There is a perception that if one is encouraged to retrofit one’s home to incorporate climate change, that this is adaptation will cost more. This may appear so, but it may not be significant compared with the large capital costs and losses that one can incur if one does not, given the notion that climate extremes are on a path to become more intense.”
He went on, “Now is the time to transfer one’s risk so that recovery will be more affordable. This calls for a more coordinated and proactive response focused on reducing the potential impact of disasters before they strike.”
Among the options available for adaptation is the replanting of trees on a hillside that is bare or exposed to reduce runoff, soil erosion and flooding downstream.
Kerr also sought to reinforce the fact that climate change will also impact the insurance and financial sectors which will have broader economic implications.
He said, “More extreme weather events will raise the number and value of claims insurers pay, which will inevitably be reflected in the premiums charged and willingness to provide cover. This can lead to unavailability or unaffordability of insurance cover for the most vulnerable of our citizens.”
Unfortunately, this is not all that we can look forward to, as Kerr said, “Most of T&T’s major urban centres and the majority of our population residences are located on the coast or floodplains of major rivers, and these settlements are growing faster than we are able to adequately plan for them.”
“And so, our communities, homes, commercial assets and infrastructure are exposed to flooding, sea-level rise, surge and inundation from hazardous seas churned up in far off distances from major weather systems.”
Kerr predicted, “Against this scenario, we can also expect to see more damage and disruption to our assets and critical infrastructure which has serious consequences for our sustainable development and growth.”
“In this context, the concern has to be the fact that climate change and related climate extremes could cripple T&T’s economy more easily than falling oil and gas prices.”
Rising sea levels threatening island nations
Of all the threats facing island nations, the rise in sea level could be the most catastrophic.
Traditionally, sea level was measured with tide gauges, but in the early 1990s, satellites began generating more comprehensive profiles of global sea level.
Using that data, NASA scientists found the average global rate of sea level rise has increased 50 per cent during the last 12 years—up to three millimetres per year from a 50-year annual average of two millimetres.
Experts attribute rising sea level to global warming and its influence on two key parameters: ocean warming (which causes water to expand) and glacial melting (which is discharging increasing amounts of freshwater directly into the sea).
Small island nations faced with the consequences of climate change must somehow adapt to it, but only a few options are available.
Islanders can either abandon threatened areas and retreat to higher ground, or build walls to hold back the sea.
The Maldivian capital of Male is partially ringed by a system of protective walls that built at the cost of US$4,000 per metre.
While these walls saved the capital from the great tsunami that struck the Indian Ocean in December 2004, it is not always so effective.
Meanwhile, the United Nations Development Programme (UNDP) has responded to the climate challenge in Small Island Developing States (SIDS) by supporting significant capacity development and engagement in international negotiations.
St Lucia’s Prime Minister Allen Chastanet said the Caribbean remained at risk of even more devastation if nothing was done to stop climate change.
Speaking at the 2017 United Nations Climate Change Conference in Bonn, Germany, Chastanet said that after the destruction experienced from hurricanes Irma, Maria and Jose that every year, the entire region had been left with feelings of fear and helplessness as the effects of climate change become more extreme.