Changes

===Projected===

===Projected===

*Increase in frequency and intensity of extreme precipitation events between now and 2100 <ref>Larson, L, Nicholas Rajkovich, and Clair Leighton. 2011. “Green Building and Climate Resilience: Understanding Impacts and Preparing for Changing Conditions.” University of Michigan, 260. </ref>

*Increase in frequency and intensity of extreme precipitation events between now and 2100 <ref>Larson, L, Nicholas Rajkovich, and Clair Leighton. 2011. “Green Building and Climate Resilience: Understanding Impacts and Preparing for Changing Conditions.” University of Michigan, 260. </ref>

* “The analysis indicates that there is likely to be an obvious warming trend with time over the entire province. The increase in average temperature is likely to be varying within [2.6, 2.7]8C in the 2030s, [4.0, 4.7]8C in the 2050s, and [5.9, 7.4]8C in the 2080s. Likewise, the annual total precipitation is projected to increase by [4.5, 7.1]% in the 2030s, [4.6, 10.2]% in the 2050s, and [3.2, 17.5]% in the 2080s. Furthermore, projections of rainfall intensity–duration–frequency (IDF) curves are developed to help understand the effects of global warming on extreme precipitation events. The results suggest that there is likely to be an overall increase in the intensity of rainfall storms. Finally, a data portal named Ontario Climate Change Data Portal (CCDP) is developed to ensure decision-makers and impact researchers have easy and intuitive access to the refined regional climate change scenarios.”  in Wang et al 2015

* “The analysis indicates that there is likely to be an obvious warming trend with time over the entire province. The increase in average temperature is likely to be varying within:

*2.6 - 2.7 °C in the 2030s,  

*4.0 - 4.7 °C in the 2050s, and  

*5.9 - 7.4 °C in the 2080s.}}

Likewise, the annual total precipitation is projected to increase by:

*4.5 - 7.1 % in the 2030s,  

*4.6 - 10.2 % in the 2050s, and  

*3.2 - 17.5 % in the 2080s.}}

Furthermore, projections of rainfall intensity–duration–frequency (IDF) curves are developed to help understand the effects of global warming on extreme precipitation events. The results suggest that there is likely to be an overall increase in the intensity of rainfall storms. Finally, a data portal named Ontario Climate Change Data Portal (CCDP) is developed to ensure decision-makers and impact researchers have easy and intuitive access to the refined regional climate change scenarios.” <ref>Wang, Xiuquan, Guohe Huang, Jinliang Liu, Zhong Li, and Shan Zhao. 2015. “Ensemble Projections of Regional Climatic Changes over Ontario, Canada.” Journal of Climate 28 (18):7327–46. https://doi.org/10.1175/JCLI-D-15-0185.1.</ref>

* “Some researchers, however, have demonstrated that the volume (Kuchenbecker et al. 2010, in Germany; cited in Bendel et al. 2013), frequency (Bendel et al. 2013, in Germany; Fortier and Mailhot 2014, May and October in Canada) or mean annual duration (Fortier and Mailhot 2014,in Canada) of CSOs should increase in the future climate. Logically, these increases will cause water quality to deteriorate in urban rivers – impacts that could be more severe as a result of increased water temperature.”  St-Hilaire et al 2016

* “Some researchers, however, have demonstrated that the volume (Kuchenbecker et al. 2010, in Germany; cited in Bendel et al. 2013), frequency (Bendel et al. 2013, in Germany; Fortier and Mailhot 2014, May and October in Canada) or mean annual duration (Fortier and Mailhot 2014,in Canada) of CSOs should increase in the future climate. Logically, these increases will cause water quality to deteriorate in urban rivers – impacts that could be more severe as a result of increased water temperature.”  St-Hilaire et al 2016

** For York Region: “• Of all temperature variables, the minima are anticipated to increase the most significantly by the 2050s in all seasons and on an annual basis (i.e. minimum temperature, average minimum temperatures) • Precipitation is expected to increase annually and over most months; however, may in fact remain relatively consistent or decrease compared with the current climate for the summer season • Extreme events are anticipated to become more frequent and more extreme. • Extreme heat indicators demonstrate that the number of days by the 2050s experiencing extreme temperatures will increase significantly. On the other hand extreme cold events are anticipated to decrease correspondingly by the 2050s, where the number of days exhibiting extremely cold temperatures could decrease • Extreme precipitation events are likely to increase in magnitude and in frequency, particularly in the summer time when convective activity is highest in and surrounding York Region. The future trend of extreme precipitation intensity; however, is unclear. It is recommended that a conservative approach should be taken in planning and adapting for extreme precipitation events. • The growing season in York Region is expected to lengthen by over 30 days by the 2050s. With this, the start date will shift earlier and the end date will shift later in the year. It is less certain, but more likely than not, that drier conditions will be present throughout the growing season in the 2050s as a result of no significant increase in precipitation over summer months and significant increases in temperatures.”  OCC et al, 2016

** For York Region: “

*Of all temperature variables, the minima are anticipated to increase the most significantly by the 2050s in all seasons and on an annual basis (i.e. minimum temperature, average minimum temperatures)

*Precipitation is expected to increase annually and over most months; however, may in fact remain relatively consistent or decrease compared with the current climate for the summer season

*Extreme events are anticipated to become more frequent and more extreme. • Extreme heat indicators demonstrate that the number of days by the 2050s experiencing extreme temperatures will increase significantly. On the other hand extreme cold events are anticipated to decrease correspondingly by the 2050s, where the number of days exhibiting extremely cold temperatures could decrease

*Extreme precipitation events are likely to increase in magnitude and in frequency, particularly in the summer time when convective activity is highest in and surrounding York Region. The future trend of extreme precipitation intensity; however, is unclear. It is recommended that a conservative approach should be taken in planning and adapting for extreme precipitation events.

*The growing season in York Region is expected to lengthen by over 30 days by the 2050s. With this, the start date will shift earlier and the end date will shift later in the year. It is less certain, but more likely than not, that drier conditions will be present throughout the growing season in the 2050s as a result of no significant increase in precipitation over summer months and significant increases in temperatures.”<ref>OCC, GLISA, Clean Air Partnership. 2016. “Historical and Future Climate Trends in York Region.”</ref>

* “If [winter] precipitation falls as rain instead of snow, which may actually occur more frequently in temper- ate regions with climate change, phosphorus concentrations in winter have the potential to be equivalent to those observed in other seasons due to the ubiquitous impacts of runoff events.”  Long et al 2014, a study done in Hamilton, ON

* “If [winter] precipitation falls as rain instead of snow, which may actually occur more frequently in temper- ate regions with climate change, phosphorus concentrations in winter have the potential to be equivalent to those observed in other seasons due to the ubiquitous impacts of runoff events.”  Long et al 2014, a study done in Hamilton, ON

* “Another potential impact of climate change on summer nutrient conditions that has been discussed in the literature is an increase of summer soluble reactive phosphorus (SRP) concentrations in creeks during low flow conditions due to temperature-dependent release from riverine sediments.”  Long et al 2014

* “Another potential impact of climate change on summer nutrient conditions that has been discussed in the literature is an increase of summer soluble reactive phosphorus (SRP) concentrations in creeks during low flow conditions due to temperature-dependent release from riverine sediments.”  Long et al 2014

* “CC effects were on average two orders of magnitude greater than LU impacts on mean daily stream T. LU change affected stream T primarily in headwater streams, on average up to 2.1°C over short durations, and projected CC affected stream T, on average 2.1 - 3.3°C by 2060.” <ref> Daraio and Bales 2014 – a modelling study that assesses the effects of land use vs climate change on urban stream temperatures </ref>

* “CC effects were on average two orders of magnitude greater than LU impacts on mean daily stream T. LU change affected stream T primarily in headwater streams, on average up to 2.1°C over short durations, and projected CC affected stream T, on average 2.1 - 3.3°C by 2060.” <ref> Daraio and Bales 2014 – a modelling study that assesses the effects of land use vs climate change on urban stream temperatures </ref>

*Higher temperatures, greater annual precipitation, larger precipitation events, increase in frequency of high flow events. Future climate scenarios predict a 40% increase in future TSS loading. Return periods for critical flows are reduced in future scenarios, while larger storms will be more frequent. Baseflow will decrease with potential impacts on rates of stream aggradation. Increased risk of erosion damages to infrastructure . Stream crossings may need to be larger. Erosion thresholds exceeded more frequently. Greater sediment loading in watercourses. Combines with higher peak flows and lower baseflow, altered sediment transport regimes could change the way our rivers form and adjust. Potential change in vegetation, habitat with increase of invasive species, drying wetlands, stress on fish species in warm and turbid waters.  Karen Hofbauer 2016 NCD 2016 Conference Presentation. Need to contact her in few months to obtain a draft of the study. Based in Hamilton – good local example of potential impacts of climate change to local streams and rivers.

*Higher temperatures, greater annual precipitation, larger precipitation events, increase in frequency of high flow events. Future climate scenarios predict a 40% increase in future TSS loading. Return periods for critical flows are reduced in future scenarios, while larger storms will be more frequent. Baseflow will decrease with potential impacts on rates of stream aggradation. Increased risk of erosion damages to infrastructure . Stream crossings may need to be larger. Erosion thresholds exceeded more frequently. Greater sediment loading in watercourses. Combines with higher peak flows and lower baseflow, altered sediment transport regimes could change the way our rivers form and adjust. Potential change in vegetation, habitat with increase of invasive species, drying wetlands, stress on fish species in warm and turbid waters.  Karen Hofbauer 2016 NCD 2016 Conference Presentation. Need to contact her in few months to obtain a draft of the study. Based in Hamilton – good local example of potential impacts of climate change to local streams and rivers.

===Concerns with projections===

===Concerns with projections===

*Even if we significantly reduce GHGs, the impacts of climate change will continue.

*Even if we significantly reduce GHGs, the impacts of climate change will continue.