The Impacts of Climate Change on the Number of Days Available for Outdoor Horse Riding Activities in the York Regional Forest, Ontario, Canada A Rapid Assessment of the Impacts of Climate Change (RAICC)
By: Evelyn Marsch 999 299 726
Thursday, December 1, 2011 EES1117 Climate Change Impact Assessment University of Toronto, Scarborough
Executive Summary This rapid assessment of the impacts of climate change assesses how changes in future climate will impact the number of days available for outdoor horseback riding activities in the York Regional Forest located in Southern Ontario, Canada. For businesses dependent on riders using the York Regional Forest it is important to understand how climate will affect the ability to use the forest for trail riding. Trail riding and other outdoor riding activities make up a large fraction of the $2.6 billion a year equine industry in Ontario. Past climate data was accessed from the National Climate Data and Information Archive online, and it was found that the number of past days available have increased by approximately 2 weeks since 1981, with a total of approximately 270 currently available annually. Minimum and mean winter temperatures are the components driving this increase. Future climate data was acquired using the Canadian Global Climate Model (CGCM) with a T63 resolution accessible from the Canadian Centre for Climate Modelling and Analysis online database. This data was validated and used to project future climate using an A2 climate scenario. These projections were used to predict a 4 week decrease between 2010 and 2100 in the annual number of days available for outdoor riding. This is only a reduction of 2 weeks from the 1981 values and should not have a significant impact on the businesses dependent on being able to ride outdoors in the York Regional Forest.
Introduction Horseback riding has always been a popular Canadian past-time, particularly in Ontario, where most horseback riding occurs recreationally. Other than a small fraction of riding that occurs indoors in climate controlled arenas or racetracks, most horseback riding is dependent on the weather, particularly those riding activities that can only occur outdoors. Many factors have been suggested to explain variations in outdoor trail use, but seasonality and weather events are among the most significant (Reynolds Kim, D et. al., 2007). Therefore, due to the weather, particularly temperature, riders are limited in the number of days available to use the forest. This Rapid Assessment of the Impacts of Climate Change (RAICC) evaluates the potential effects of climate change on outdoor horseback riding activities, specifically the number of days available for outdoor riding activities based on daily mean temperatures. The particular area chosen for this is assessment is the York Regional Forest in Southern Ontario, chosen for its high volume of horse riders and related businesses dependent on the use of the forest for horseback riding activities.
Horseback Riding in Ontario The equine industry has been growing and evolving in Ontario over the past twenty-five years. While the equine industry has been expanding in recent years, most notably with a 16.7% increase in the number of horses between 2001 and 2006, there has been limited investigation of this sector by either provincial or municipal government agencies (Wilton and Caldwell, 2009). The equine industry in Ontario is very diverse and is distributed spatially across the province with various nodes of concentration close to urban areas such as the Greater Toronto Area and Ottawa. In total in Ontario, the horse population was estimated to be 379,412 in 2006 by a study conducted by Wilton and Caldwell (2009). In that same study the number of horse facilities was estimated to be
62,417 and the estimated annual expenditure per horse in Ontario was $6,980. 80,000 people are estimated to be directly employed in the industry. Overall in 2006 the estimated total provincial annual expenditures on horses in Ontario was $2.6 billion with an additional $6.9 billion invested or in fixed assets (Wilton and Caldwell, 2009). With continued expansion of the industry comparable to what has been seen in the past, these figures could be significantly greater by 2011. The equine industry in Ontario is comprised of a broad range of racing, sport, recreation, and breed interests. The majority of horse related activities occur outdoors; many of which would be very difficult to undertake indoors. Additionally, even those activities that can and do occur indoors, are very rarely climate controlled and therefore almost all riding activities are climate dependent in some form. There is both a thriving harness horse racing industry and a thoroughbred racing industry as well as emerging quarter horse racing interests, which occur mostly on outdoor racetracks. Eventing, foxhunting, endurance riding and pleasure riding also occur outdoors. Additional horse sports such as show-jumping, dressage, hunters, western reining, driving and showing heavy/miniature horses, are well represented in Ontario but are riding activities that mainly occur indoors and can therefore technically occur in climate controlled environments and can avoid being affected by climate change. Table 1: Participation in Horse Riding Activities in Ontario
Source: Wilton and Caldwell, 2009
In this particular climate study, the main activity of interest is trail riding; a riding activity that can only occur outdoors. Trail riding is found in the “other” category, along with several other activities that can only occur outdoors. As of 2006, 25% of registered riders in Ontario participated in „other‟ horseback riding activities. With an additional 18% participating in „eventing‟ and 4% „endurance‟, almost half of all riders are estimated to partake in activities that can only occur outside and are therefore dependent on climate.
The York Regional Forest The York Regional Forest (YRF), owned and managed by the Regional Municipality of York, was first established in 1924. Today the Regional Forest is 2
comprised of 20 tracts totalling over 2200 hectares (5400 acres), in four local municipalities in York Region (York Region Natural Heritage & Forestry, March 2010). A public access forest, the YRF is under the management direction of the Ontario Ministry of Natural Resources and in turn has become one of the most successful restorations of a degraded landscape in North America (York Region Website). There are many recreational activities that take place in the YRF One of the most popular activities being horseback riding, otherwise known as trail riding. There are many equine business surrounding the YRF, which allow riders direct access to the forest. Weather and season permitting, this forest provides optimal conditions for trail riding. The trails have soft ground, are mostly devoid of debris and are maintained regularly. Motor vehicles are also banned from this forest. A high volume of pine trees and few wet or swampy areas avoid high numbers of mosquitoes and other pests. These conditions have led to the success of many equine businesses in the area who can provide access to this forest to horse owners and riders who prefer to ride outdoors in a forest setting.
Exposure Unit For this assessment, the horse is the most sensitive unit being exposed to the environment. The thermoneutral zone for horses is reported to be between 5–25⁰C (Morgan, 1998). Although this range is influenced by relative humidity, the animal‟s condition (body fat) and hair coat, and the opportunity to acclimate to environmental conditions, this is a legitimate literature source that has set out a specific range of temperatures to ensure a healthy horse under working conditions. At temperatures below the thermoneutral zone, the animal must increase energy production to keep body core temperature from decreasing. At temperatures above the thermoneutral zone, the animal must dissipate energy to cool its body (Ott, 2004). A horse can encounter both selfinduced heat stress and environmental heat stress. Self-induced heat stress occurs when the animal is worked to the extent that its cooling system cannot keep up with the heat produced from the activity (Febbraio et al., 1994). Anhidrotic horses (or those with any kind of disorder resulting in lack of sweating) often encounter this challenge, even when the animal is within the thermoneutral zone and would therefore be even more susceptible to a warming climate. Environmental heat stress occurs when the ambient temperature, or temperature/RH combination, exceeds the thermoneutral zone, and may be exacerbated by increased heat load due to work (Ott, 2004). Extreme heat stress causes more severe consequences in horses and is more difficult to combat than cold stress. Once a horse experiences excessive heat production within the body, the only way to aid the animal and avoid metabolic complications is to seize all work and apply a constant stream of cold water to the largest muscles of the animal. Cold temperatures are slightly easier to combat, as the impacts of cold weather can be reduced by ensuring the horse has a sufficient winter coat or wears appropriate protective blankets and hoods (Ott, 2004). Particularly under sweating conditions it is very important to keep a horse warm.
Methodology The main factor limiting the ability to ride a horse outdoors is mean temperature. A range of 5–25⁰C mean temperature was applied to climate data to determine the number of days available. In order to calculate the number of historical and future days available for trail riding annually (based only on temperature), access to weather data from the National Climate Data and Information Archive online provided the historical
climate data necessary. 30 years of data, ranging from 1981 to 2010 was used, collected at the Gormley-Ardenlee weather station. This station was picked due to a mostly complete data set and its close proximity to the YRF. The 30 year past dataset from this station was almost complete. The only missing values included January through November 1994. Applying the 3 and 5 rule, any 1994 data was therefore considered unusable and 1994 was removed entirely. To determine future values, 140 years (1961- 2100) of modelled data was downloaded from the Canadian Centre for Climate Modelling and Analysis online database. The Canadian 3rd generation coupled Global Climate Model (CGCM) with T63 resolution was used. An A2 climate scenario was applied to derive future data and then validated and adjusted using an ensemble technique. Once projected mean temperature from 2011 through 2100 was determined, this data was used to determine future riding days within the 5–25⁰C mean temperature range. Precipitation Precipitation is only a factor in direct relation to temperature as precipitation does not affect the horse directly and therefore was not considered a factor for this assessment. A horse will only experience the consequences of being wet under extreme temperature conditions, particularly when cold, but also with effects to RH. Precipitation does affect ground conditions for riding, referred to as “footing”. Most forests that have become popular for horseback riding did so because the footing is optimal with dry, sandy soils. Moisture on the ground can make some footing wet, muddy and slippery, however for the most part the footing in the YRF is dry and sandy. Significant affects to even dry, sandy footing does occur but only when there is a large amount of rainfall followed by temperatures below 0˚C. This is however well outside the thermoneutral zone of the horse and would exclude these days due to temperatures below 5˚C in any case.
Past Annual Mean Temperature In order to calculate the number of historical days available for trail riding annually based on temperature, weather data from the National Climate Data and Information Archive (NCDIA) online provided 30 years of historical data, ranging from 1981 to 2010. Data was collected at the Gormley-Ardenlee weather station as this station was within the closest proximity to the YRF. Upon investigation of the changes in mean temperature since 1980, it was found that the mean temperature has increased approximately 2⁰C overall.
Table 2: Annual Mean Temperature for NCDIA Climate Data, Gormley Ontario, 1981-2010
Climate Drivers When mean, minimum and maximum temperatures are compared, it is noticeable that the temperature component driving the overall increase is the minimum temperature. With respect to a horse‟s thermoneutral zone, this has aided with the increase in the number of days available because it is reducing the number of days below 5°C at a greater rate than the days over 25°C are increasing. Table 3: Temperature Comparison for Annual Climate Data, Gormely Ontario, 19812010
As well as an increase in overall minimum annual temperatures, a greater increase is seen with winter temperatures. On a seasonal basis, winter temperatures have increased approximately 0.5°C more than the overall average increase. This is synonymous with the claims from a 2008 climate change report from the York Region, that the overall winter season is getting shorter (York Region, 2008). This increase in winter temperatures is also likely responsible for the minimum temperature driving the temperature increase. Warming temperatures, particularly a reduction in colder temperatures and the winter
season is an advantage for the horse riding industry because it increases the number of days available and expands the “riding season”. Table 4: Seasonal Temperature for NCDIA Climate Data, Gormely Ontario, 19812010
Climate Extremes Although technically most horses are perfectly comfortable well below 5°C and slightly above 25°C, the equine extremes for horses under work have been established according to Ott (2004) who recorded significant stress on a horse‟s metabolism under even light working conditions outside the thermoneutral zone. In terms of extreme equine heat days, based on days of mean temperature greater than 25°C, an increase of about 5 days has been observed between 1981 and 2010. Table 5: Number of Extreme Heat Days Based on Equine Thermoneutral Zone
On the contrary, the number of extreme equine cold days, based on days of mean temperature less than 5°C, has decreased about 17 days between 1981 and 2010.
Table 6: Number of Extreme Cold Days Based on Equine Thermoneutral Zone
The number of extreme cold days have decreased over 3 times greater than the number of heat days have increased over the past 30 years. This has resulted in an overall increase in the average number of days per year within the thermonetral zone.
Past and Current Days Available for Outdoor Horse Riding Activities The number of days available for outdoor riding were ultimately established using the horse‟s thermoneutral zone. All the days of the year were considered as potentially available, even throughout the winter months. Although many horse riding operations close down during the winter months, operating only during the “riding season”, it is already noticeable that the increase in days available is expanding the riding season and making outdoor riding possible throughout most of the year. Technically however, winter riding, on days where temperatures are 5°C or above, is highly possible particularly because snow is a perfectly acceptable footing for riding, especially when softened by warmer air temperatures. Based on mean temperatures, the total increase of days available for outdoor riding activities between 1981 and 2010 was approximately 14 days. In 2010 there were about 270 total days available for outdoor riding activities. This means that currently, a sufficient amount of rideable days are available to sustain a riding operation based on outdoor riding activities. Table 7: Number of Days Available for Outdoor Horse Activities based on Mean Temperature, 1981-2010
Future Climate Projections To determine future values, 140 years (1961- 2100) of modelled data was downloaded from the Canadian Centre for Climate Modelling and Analysis online database. This database was used because it was free and easily accessible. The 3rd generation coupled Canadian Global Climate Model (CGCM) with T63 resolution was used. The coordinates for the actual location for the assessment area used in the CGCM was 47-100. The CGCM was used because it was the most recent and updated version of the models easily available with the greatest resolution. Climate Scenarios and Model Validation
Upon validation against the other 23 global climate models, the CGCM T63 had the best values for temperature as can be seen in the validation scatterplot below. Upon further validation, the projected mean temperature models where graphed, showing the validated ensemble group containing the two Canadian CGMs within a one deviation standard on the scatterplot. The validated ensemble was found to be distributed fairly evenly between the maximum and minimum modelled data. All 3 climate scenarios available were applied separately to compose modelled data and the backcasts compared to the observed data. It was found that all 3 scenarios backcasted mean temperatures that were very close to the observed data; data only had to be adjusted about 0.3째C. It was found however that the A2 climate scenario was the closest overall to the observed data. Since past observed data has already seen quite significant changes over the past 30 years and the A2 modelled data showed the closest correlation to the real data, the A2 climate scenario was ultimately applied to derive future data for this assessment.
Projected Future Temperatures Using the A2 scenario with the CGCM T63, it was found that there is an overall projected increase of approximately 7째C over the 130 year assessment period. For the future, this means an increase of approximately 5째C.
Table 8: Past and Future A2 Climate Scenario for Annual Mean Temperature for York Regional Forest, Ontario, 1981-2100
With respect to extreme equine heat days, there is a projected increase of 56 days in the 90 years between 2011 and 2100. Again, this is based on days of mean temperatures greater than 25°C. This means that there will be 56 days a year on average removed from the riding season due to temperatures being too high by 2100. This means a total of almost 80 days a year not being available for riding due to heat. There are also a few observed “spikes” in the number of projected extreme equine heat days, where the number of days reaches well over 100. If these projections are correct then in some years, outdoor riding will be more severely affected than the average in terms of unavailable days. Table 9: Number of Future Extreme Equine Heat Days
Overall, the number of extreme equine cold days is projected to decrease an average of 41 days between 2011-2100. This is adding an additional 41 days to the annual available days.
Table 10: Future Number of Equine Cold Days
Future Days Available for Outdoor Horse Riding activities As with the past calculated annual number of days available for outdoor horseback riding activities, future days were determined using the horseâ€&#x;s thermoneutral zone. Despite seeing an increase of about two weeks between 1980 and 2010, in total within the entire 130 year assessment period from 1981 to 2100, there was a decrease of about 2 weeks. Upon closer investigation is it notable that although the number of days available decreases about 2 weeks over total time period (1981-2100), the number of days available decreases approximately 4 weeks between 2020 and 2100. The number of available days peaks at around year 2020, with a total increase of 19 days from 1981. This is due to the decrease in the number of extreme cold days exceeding the increase in the number of extreme heat days. After 2020, the increase in the number of extreme heat days begins to exceed the decrease in extreme cold days, and the number of available days begins to decline. By the 2060s the average annual number of days available is projected to reach the original 1981 levels of approximately 260 days. By 2100 the total number of days available per year for outdoor riding activities will decrease about 30 days from current 2011 levels, resulting in approximately 240 days available per year in the future.
Table 11: Number of Future Days Available for Outdoor Horse Riding Activities based on Mean Temperature
Conclusions In conclusion, by 2100, the projected average annual number of days available for horseback riding outdoors is estimated at approximately 250 days. The initial gain of available days up until 2020 is mainly due to a reduction in the number of cold days. However, the overall major loss of days will be due to heat in the future, and fluctuations in the future will no longer be driven by minimum and mean winter temperatures, but an increase in maximum and summer temperatures.
Discussion Over the next 90 years, even with the changes in the number of days, there will be a sufficient number of annual days available to sustain a business dependent on being able to ride horses in the YRF. Additionally, it has been noted by Ott (2004) that not only do horses have good ability to acclimate to warmer temperatures given sufficient time, but there are certain breeds that are naturally more heat tolerant. Currently, common breeds chosen in Canada are those specifically tolerant to colder temperatures, but for the future as temperatures generally increase, the equine industry may see shift to more heat tolerant breeds. Other observable changes may include adjustments in riding times to avoid the hottest times of the day. Even at present time, many outdoor equine operations do not ride between noon and 3pm to avoid the times of day with excessive heat. The equine industry may even see a shift in riding season, whereby the winter months are no longer considered the â€œoff seasonâ€?, and some riding operations may shut down during the summer months. In general however, climate change will not be affecting the equine industry in Ontario significantly 90 years into the future.
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